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Multiface ROM Collection Project.
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jmk
Sep 30, 2012, 6:33:54 PM9/30/12
to
While I am posting here, I may as well mention my Multiface ROM Collection Project:
http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm
On this page you will find details of the ROM versions that have been found for Multiface 1, 128, 3 and the MultiPrint.
Also on that page, you will find a utility (supplied as a TAP file) to run on your Spectrum to identify and dump the ROM. Using the raw power of a CRC-32 routine running slowly on the Z80, it can identify all known ROMs and even has a list of BASIC ROMs as well, so that it can tell if your interface failed to page in!
From reading old adverts and reviews, I spotted a number of interesting versions (mostly from the Multiface One). Limited toolkits, versions that only had 2K of RAM and a version that supported the Kempston Disc interface. None of these versions have been found. If you have one of the Multiface or MultiPrint interfaces could you please check them to see if you have one of the unknown ones, even if it is just a different CRC version.
Thanks.
http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm
On this page you will find details of the ROM versions that have been found for Multiface 1, 128, 3 and the MultiPrint.
Also on that page, you will find a utility (supplied as a TAP file) to run on your Spectrum to identify and dump the ROM. Using the raw power of a CRC-32 routine running slowly on the Z80, it can identify all known ROMs and even has a list of BASIC ROMs as well, so that it can tell if your interface failed to page in!
From reading old adverts and reviews, I spotted a number of interesting versions (mostly from the Multiface One). Limited toolkits, versions that only had 2K of RAM and a version that supported the Kempston Disc interface. None of these versions have been found. If you have one of the Multiface or MultiPrint interfaces could you please check them to see if you have one of the unknown ones, even if it is just a different CRC version.
Thanks.
Brian Gaff
Oct 1, 2012, 8:03:39 AM10/1/12
to
Whatever happened to the guy, watt was heis name, Sacha was it?
Brian
--
From the Sofa of Brian Gaff Reply address is active
"jmk" <jmc...@jmk1.freeserve.co.uk> wrote in message
news:039f8df6-fe37-466b...@googlegroups.com...
Brian
--
From the Sofa of Brian Gaff Reply address is active
"jmk" <jmc...@jmk1.freeserve.co.uk> wrote in message
news:039f8df6-fe37-466b...@googlegroups.com...
jmk
Oct 1, 2012, 8:46:29 AM10/1/12
to Brian Gaff
Do you mean Alexander Goldscheider? I sent an email to his Romantic Robot address late last week. I've not had a reply yet.
On Monday, October 1, 2012 1:03:39 PM UTC+1, Brian Gaff wrote:
> Whatever happened to the guy, watt was his name, Sacha was it? Brian -- From the Sofa of Brian Gaff Reply address is active
On Monday, October 1, 2012 1:03:39 PM UTC+1, Brian Gaff wrote:
> Whatever happened to the guy, watt was his name, Sacha was it? Brian -- From the Sofa of Brian Gaff Reply address is active
Volker Bartheld
Oct 1, 2012, 9:36:51 AM10/1/12
to
Hi!
On Sun, 30 Sep 2012 15:33:54 -0700 (PDT), jmk wrote:
> While I am posting here, I may as well mention my Multiface ROM
> Collection Project: http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm
> [...]
get to test my version.
> Limited toolkits, versions
> that only had 2K of RAM and a version that supported the Kempston Disc
> interface. None of these versions have been found. If you have one of
> the Multiface or MultiPrint interfaces could you please check them to
> see if you have one of the unknown ones, even if it is just a different
> CRC version.
Would be way cool to mod the ROM (or piggyback some kind of EEPROM), so I
can use the magic button to transfer a snapshot to PC...
Cheers,
Volker
--
@: I N F O at B A R T H E L D dot N E T
3W: www.bartheld.net
On Sun, 30 Sep 2012 15:33:54 -0700 (PDT), jmk wrote:
> While I am posting here, I may as well mention my Multiface ROM
> Collection Project: http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm
> From reading old adverts and reviews, I spotted a number of interesting
> versions (mostly from the Multiface One).
I have the MF-1. Epic hardware! Unfortunately, it can take a while until I
> versions (mostly from the Multiface One).
get to test my version.
> Limited toolkits, versions
> that only had 2K of RAM and a version that supported the Kempston Disc
> interface. None of these versions have been found. If you have one of
> the Multiface or MultiPrint interfaces could you please check them to
> see if you have one of the unknown ones, even if it is just a different
> CRC version.
can use the magic button to transfer a snapshot to PC...
Cheers,
Volker
--
@: I N F O at B A R T H E L D dot N E T
3W: www.bartheld.net
jmk
Oct 2, 2012, 9:05:45 AM10/2/12
to dr_ve...@freenet.de
On Monday, October 1, 2012 2:36:05 PM UTC+1, Volker Bartheld wrote:
> I have the MF-1. Epic hardware! Unfortunately, it can take a while until I get to test my version.
Anything would help. I would quickly become bankrupt if I tried to pick up every Multiface that turns up on eBay (at those prices).
> I have the MF-1. Epic hardware! Unfortunately, it can take a while until I get to test my version.
> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), so I can use the magic button to transfer a snapshot to PC... Cheers, Volker
Volker Bartheld
Oct 2, 2012, 12:04:23 PM10/2/12
to
Hi!
>> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), so
>> I can use the magic button to transfer a snapshot to PC... Cheers,
>> Volker
[1]? I somehow remember that my friend's Multiface could do this, while
mine (being an early adopter and therefore paying the price) couldn't.
I gotta have a look at it when I'm visiting the computer garage^W^W home of
retired computers again - let's hope that Tapir-ing the program to the
Line-Out socket of my Thinkpad will work...
Cheers,
Volker
[1] The manual (see
ftp://ftp.worldofspectrum.org/pub/sinclair/hardware-info/Multiface1_Manual.pdf)
says so, but I'm still not entirely convinced...
>> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), so
>> I can use the magic button to transfer a snapshot to PC... Cheers,
>> Volker
On Tue, 2 Oct 2012 06:05:45 -0700 (PDT), jmk wrote:
> Yes. You could write a program that fits in the Multiface RAM to do
> something like that... There's a few bytes in the RAM that you set to
> autorun a program when you press the red button.
Are you 100% sure that this was possible with all MF-1 firmware versions
> Yes. You could write a program that fits in the Multiface RAM to do
> something like that... There's a few bytes in the RAM that you set to
> autorun a program when you press the red button.
[1]? I somehow remember that my friend's Multiface could do this, while
mine (being an early adopter and therefore paying the price) couldn't.
I gotta have a look at it when I'm visiting the computer garage^W^W home of
retired computers again - let's hope that Tapir-ing the program to the
Line-Out socket of my Thinkpad will work...
Cheers,
Volker
[1] The manual (see
ftp://ftp.worldofspectrum.org/pub/sinclair/hardware-info/Multiface1_Manual.pdf)
says so, but I'm still not entirely convinced...
jmk
Oct 2, 2012, 1:26:47 PM10/2/12
to dr_ve...@freenet.de
On Tuesday, October 2, 2012 5:03:37 PM UTC+1, Volker Bartheld wrote:
> Hi! >> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), so >> I can use the magic button to transfer a snapshot to PC... Cheers, >> Volker On Tue, 2 Oct 2012 06:05:45 -0700 (PDT), jmk wrote: > Yes. You could write a program that fits in the Multiface RAM to do > something like that... There's a few bytes in the RAM that you set to > autorun a program when you press the red button. Are you 100% sure that this was possible with all MF-1 firmware versions [1]? I somehow remember that my friend's Multiface could do this, while mine (being an early adopter and therefore paying the price) couldn't.
Now you are intriguing me. ;)
> Hi! >> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), so >> I can use the magic button to transfer a snapshot to PC... Cheers, >> Volker On Tue, 2 Oct 2012 06:05:45 -0700 (PDT), jmk wrote: > Yes. You could write a program that fits in the Multiface RAM to do > something like that... There's a few bytes in the RAM that you set to > autorun a program when you press the red button. Are you 100% sure that this was possible with all MF-1 firmware versions [1]? I somehow remember that my friend's Multiface could do this, while mine (being an early adopter and therefore paying the price) couldn't.
You may have an interesting version there! I'd be grateful if you were to ID & Dump it.
Stacey
Oct 2, 2012, 8:52:17 PM10/2/12
to
I piggy backed a 8K RAM chipt to the Rom on a IF1. With a hardware
switch I could us the MF1 rom or my code which had written, including a
cheat finder and a dissasmbler usuing a 42 column screen output.
Sold it all off ages ago on ebay (a lot including a 48K spectrum, 128K
toast rack and a +3 with loads of games), including the source code
copies. Wish I sill had that source code!
-Stacey
switch I could us the MF1 rom or my code which had written, including a
cheat finder and a dissasmbler usuing a 42 column screen output.
Sold it all off ages ago on ebay (a lot including a 48K spectrum, 128K
toast rack and a +3 with loads of games), including the source code
copies. Wish I sill had that source code!
-Stacey
Volker Bartheld
Oct 8, 2012, 8:19:55 AM10/8/12
to
Hi James!
On Sun, 30 Sep 2012 15:33:54 -0700 (PDT), jmk wrote:
to you). Advantage is that this can be transferred from PC to IF-1 using
spxfr without the need to fiddle with audio cables etc. It will also speed
up exporting the MF-1 ROM snapshot.
If I'm lucky, I can try this out later today. Stay tuned!
Volker
On Sun, 30 Sep 2012 15:33:54 -0700 (PDT), jmk wrote:
> While I am posting here, I may as well mention my Multiface ROM Collection Project:
> http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm
I converted your mfiddump.tap to .snp format (see today's mail that I sent
> http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm
to you). Advantage is that this can be transferred from PC to IF-1 using
spxfr without the need to fiddle with audio cables etc. It will also speed
up exporting the MF-1 ROM snapshot.
If I'm lucky, I can try this out later today. Stay tuned!
Volker
jmk
Oct 8, 2012, 9:21:41 PM10/8/12
to dr_ve...@freenet.de
On Monday, October 8, 2012 1:19:05 PM UTC+1, Volker Bartheld wrote:
> Hi James! On Sun, 30 Sep 2012 15:33:54 -0700 (PDT), jmk wrote: > While I am posting here, I may as well mention my Multiface ROM Collection Project: > http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm I converted your mfiddump.tap to .snp format (see today's mail that I sent to you). Advantage is that this can be transferred from PC to IF-1 using spxfr without the need to fiddle with audio cables etc. It will also speed up exporting the MF-1 ROM snapshot. If I'm lucky, I can try this out later today. Stay tuned!
Thanks for that, hopefully giving as many options as possible will convince people to help.
> Hi James! On Sun, 30 Sep 2012 15:33:54 -0700 (PDT), jmk wrote: > While I am posting here, I may as well mention my Multiface ROM Collection Project: > http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm I converted your mfiddump.tap to .snp format (see today's mail that I sent to you). Advantage is that this can be transferred from PC to IF-1 using spxfr without the need to fiddle with audio cables etc. It will also speed up exporting the MF-1 ROM snapshot. If I'm lucky, I can try this out later today. Stay tuned!
Looking forward to your ROM... ;)
P.S. I couldn't reply to your email because it said I needed a digital certificate...
Volker Bartheld
Oct 9, 2012, 7:50:53 AM10/9/12
to
Hi James!
>>>> Would be way cool to mod the ROM (or piggyback some kind of EEPROM),
>>>> so I can use the magic button to transfer a snapshot to PC...
- Transferring mfiddump*.snp via spxfr and IF1 worked like a charm.
- mfiddump came up with the following (unknown to mfiddump and
http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm) CRC:
FA1B8B0D.
- Calculating the CRC didn't take as long as expected.
- Dumping the MF1-ROM (32768+8192 Bytes) via IF1 and spxfr was successful.
- Digital image of the device plus ROM dump downloadable from
http://bartheld.net/temp/mf1.zip (~200kB).
- My Multiface can most certainly not execute user code "out of the box".
- When activated, it shows a menu in (and ONLY IN) the bottom two
screen rows.
- Seems like there's an E-PROM and some (undecipherable) RAMs on the PCB.
- Flashing the new firmware would IMO require an E-PROM burner and there's
still the risk of incompatible hardware.
- I tried to emulate the ROM with Gerton's WinZ80 but failed. He has all
ROMs accumulated in an undocumented file called roms.bin.
HTH,
Volker
>>>> Would be way cool to mod the ROM (or piggyback some kind of EEPROM),
>>>> so I can use the magic button to transfer a snapshot to PC...
>>> There's a few bytes in the RAM that you set to autorun a program when
>>> you press the red button.
>> Are you 100% sure that this was possible with all MF-1 firmware versions
>> [1]? I somehow remember that my friend's Multiface could do this, while
>> mine (being an early adopter and therefore paying the price) couldn't.
>>> you press the red button.
>> Are you 100% sure that this was possible with all MF-1 firmware versions
>> [1]? I somehow remember that my friend's Multiface could do this, while
>> mine (being an early adopter and therefore paying the price) couldn't.
On Tue, 2 Oct 2012 10:26:47 -0700 (PDT), jmk wrote:
> Now you are intriguing me. ;) You may have an interesting version there!
> I'd be grateful if you were to ID & Dump it.
OK, yesterday's investigation resulted in these findings:
> Now you are intriguing me. ;) You may have an interesting version there!
> I'd be grateful if you were to ID & Dump it.
- Transferring mfiddump*.snp via spxfr and IF1 worked like a charm.
- mfiddump came up with the following (unknown to mfiddump and
http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm) CRC:
FA1B8B0D.
- Calculating the CRC didn't take as long as expected.
- Dumping the MF1-ROM (32768+8192 Bytes) via IF1 and spxfr was successful.
- Digital image of the device plus ROM dump downloadable from
http://bartheld.net/temp/mf1.zip (~200kB).
- My Multiface can most certainly not execute user code "out of the box".
- When activated, it shows a menu in (and ONLY IN) the bottom two
screen rows.
- Seems like there's an E-PROM and some (undecipherable) RAMs on the PCB.
- Flashing the new firmware would IMO require an E-PROM burner and there's
still the risk of incompatible hardware.
- I tried to emulate the ROM with Gerton's WinZ80 but failed. He has all
ROMs accumulated in an undocumented file called roms.bin.
HTH,
Volker
Volker Bartheld
Oct 9, 2012, 8:11:10 AM10/9/12
to
Hi James!
On Mon, 8 Oct 2012 18:21:41 -0700 (PDT), jmk wrote:
> P.S. I couldn't reply to your email because it said I needed a digital certificate...
My emails are digitally signed. There are various reasons to do so - anti
spam measures being one of them. However I see no reason at all why you
shouldn't be able to reply to such a mail without signing your reply. Some
old versions of Outlook (Express) had a habit to fail with digital
signatures and Lotus Notes/Domino even crashed when a signature contained
more than one certificate - this is no error on my behalf, just broken
software.
Cheers,
On Mon, 8 Oct 2012 18:21:41 -0700 (PDT), jmk wrote:
> P.S. I couldn't reply to your email because it said I needed a digital certificate...
spam measures being one of them. However I see no reason at all why you
shouldn't be able to reply to such a mail without signing your reply. Some
old versions of Outlook (Express) had a habit to fail with digital
signatures and Lotus Notes/Domino even crashed when a signature contained
more than one certificate - this is no error on my behalf, just broken
software.
Cheers,
jmk
Oct 9, 2012, 1:42:02 PM10/9/12
to dr_ve...@freenet.de
On Tuesday, October 9, 2012 12:50:03 PM UTC+1, Volker Bartheld wrote:
> Hi James! >>>> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), >>>> so I can use the magic button to transfer a snapshot to PC... >>> There's a few bytes in the RAM that you set to autorun a program when >>> you press the red button. >> Are you 100% sure that this was possible with all MF-1 firmware versions >> [1]? I somehow remember that my friend's Multiface could do this, while >> mine (being an early adopter and therefore paying the price) couldn't. On Tue, 2 Oct 2012 10:26:47 -0700 (PDT), jmk wrote: > Now you are intriguing me. ;) You may have an interesting version there! > I'd be grateful if you were to ID & Dump it. OK, yesterday's investigation resulted in these findings: - Transferring mfiddump*.snp via spxfr and IF1 worked like a charm. - mfiddump came up with the following (unknown to mfiddump and http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm) CRC: FA1B8B0D. - Calculating the CRC didn't take as long as expected. - Dumping the MF1-ROM (32768+8192 Bytes) via IF1 and spxfr was successful. - Digital image of the device plus ROM dump downloadable from http://bartheld.net/temp/mf1.zip (~200kB). - My Multiface can most certainly not execute user code "out of the box". - When activated, it shows a menu in (and ONLY IN) the bottom two screen rows. - Seems like there's an E-PROM and some (undecipherable) RAMs on the PCB. - Flashing the new firmware would IMO require an E-PROM burner and there's still the risk of incompatible hardware. - I tried to emulate the ROM with Gerton's WinZ80 but failed. He has all ROMs accumulated in an undocumented file called roms.bin. HTH, Volker
Wow! Thanks a lot!
> Hi James! >>>> Would be way cool to mod the ROM (or piggyback some kind of EEPROM), >>>> so I can use the magic button to transfer a snapshot to PC... >>> There's a few bytes in the RAM that you set to autorun a program when >>> you press the red button. >> Are you 100% sure that this was possible with all MF-1 firmware versions >> [1]? I somehow remember that my friend's Multiface could do this, while >> mine (being an early adopter and therefore paying the price) couldn't. On Tue, 2 Oct 2012 10:26:47 -0700 (PDT), jmk wrote: > Now you are intriguing me. ;) You may have an interesting version there! > I'd be grateful if you were to ID & Dump it. OK, yesterday's investigation resulted in these findings: - Transferring mfiddump*.snp via spxfr and IF1 worked like a charm. - mfiddump came up with the following (unknown to mfiddump and http://www.indigobanquet.adsl24.co.uk/multiface/multiface.htm) CRC: FA1B8B0D. - Calculating the CRC didn't take as long as expected. - Dumping the MF1-ROM (32768+8192 Bytes) via IF1 and spxfr was successful. - Digital image of the device plus ROM dump downloadable from http://bartheld.net/temp/mf1.zip (~200kB). - My Multiface can most certainly not execute user code "out of the box". - When activated, it shows a menu in (and ONLY IN) the bottom two screen rows. - Seems like there's an E-PROM and some (undecipherable) RAMs on the PCB. - Flashing the new firmware would IMO require an E-PROM burner and there's still the risk of incompatible hardware. - I tried to emulate the ROM with Gerton's WinZ80 but failed. He has all ROMs accumulated in an undocumented file called roms.bin. HTH, Volker
This is definitely old. It only has Exit, Return, Save and Poke options, no Printing, no Jumping, no Toolkit.
I tried it with Genie and Lifeguard and, sure enough, it can't start them when you press the button.
The picture looks like 1 EPROM, 1 RAM chip (HM6264 = 8K) and possibly a load of small logic chips. It's possible that you have the full 8K RAM, although I can't tell for sure if all the address lines are attached. I'll have to upgrade the dumping tool to check the size of the RAM.
I think you might be able to burn an EPROM of a newer MF1 version, install it and get it to work, as long as the full 8K RAM is wired up. ROMS.BIN has the MF128 ROM at offset 0x1E000 (the info is available in the DOS version's documents), but it uses different ports from the MF1, so you can't swap them.
The CRC is calculated by a routine in contended memory, so it could be made to move a little quicker. ;)
Regarding digital IDs, when I use Outlook Express on my XP machine, it gives me the option to get a digital ID and then goes to a dead link!
Volker Bartheld
Oct 10, 2012, 10:39:49 AM10/10/12
to
Hi James!
On Tue, 9 Oct 2012 10:42:02 -0700 (PDT), jmk wrote:
> This is definitely old. It only has Exit, Return, Save and Poke options,
> no Printing, no Jumping, no Toolkit.
Jup. As said: The woes of an early adopter. Basically, I thought about
designing my own "Multiface", long before the MF-1 appeared on the market.
But those days, you couldn't simply start up EAGLE, load a few libraries,
connect some buses and signals, click on "Autoroute" and send the
CAD-/CAM-Files to some service provider.
And the parts were pretty expensive - I remember having paid big bucks for
the inevitable Z80-PIO and the bigger RAM chips to replace the upper 32k
of my Speccy and allow bank switching. Not to speak of the female part
matching the edge connector...
So erasing/burning an E-PROM, designing a PCB AND developing M/C software
to deal with backupping what the Speccy had in its RAM was way out of
reach. Today, you could emulate stuff instead of crashing GENS for the
1000th time - that's how I developed mdv2img, the tool that helped me to
create images from Microdrive cartridges.
Some 25 years ago, not even a singlestepping mode with register display
existed, so it was pretty much trial and error.
> I tried it with Genie and Lifeguard and, sure enough, it can't start them
> when you press the button.
*LOL* Yes, I failed miserably, too... ;-)
> The picture looks like 1 EPROM, 1 RAM chip (HM6264 = 8K) and possibly a
> load of small logic chips. It's possible that you have the full 8K RAM,
> although I can't tell for sure if all the address lines are attached.
I never disassembled the MF-1 ROM nor did I care much about how it worked.
As long as it worked. Did it copy part of the Spectrum's RAM to it's own
RAM to be able to create the BASIC loader plus SCREEN$ and 48K RAM? I
remember my MF-1 corrupting parts of the screen, so it probably couldn't
create a perfect copy of the snapshot.
> I'll have to upgrade the dumping tool to check the size of the RAM.
Are there any schematics of the MF-1 around? IF-1/2 and Microdrives are
pretty well documented and lately even the ULA has been reverse engineered
(hats off to Chris Smith, he did an unbelievably cool job - see
http://www.zxdesign.info/book/insideULA.shtml for details!) - but I wasn't
able to get info on how the MF-1 worked.
Probably just generating an NMI, paging out the Speccy's ROM and paging in
the MF-1 ROM and RAM instead. What I didn't know is, that you could trigger
that paging mechanism via software (addresses 9Fh/1Fh). And I never
bothered to investigate how an image is actually restored.
> I think you might be able to burn an EPROM of a newer MF1 version,
> install it and get it to work, as long as the full 8K RAM is wired up.
Indeed. But I still have no E-PROM burner. In the age of GBs of Flash RAM,
this probably will have to be stolen out of a museum... ;-)
> ROMS.BIN has the MF128 ROM at offset 0x1E000 (the info is available in
> the DOS version's documents), but it uses different ports from the MF1,
> so you can't swap them.
Ah. OK.
> The CRC is calculated by a routine in contended memory, so it could be
> made to move a little quicker. ;)
Hey, 2s (IIRC) is good enough for me.
> Regarding digital IDs, when I use Outlook Express on my XP machine, it
> gives me the option to get a digital ID and then goes to a dead link!
Lame. I gave up on Outlook years ago. TheBat (Ritlabs) is so much better,
that I never felt the urge to look back.
Cheers,
Volker
P.S.: Make sure to read Andrew Pennel's blog about how he wrote his forst
book, "Master Your ZX Microdrive":
http://blogs.msdn.com/b/andypennell/archive/2009/04/27/you-know-you-re-old-when-the-copyright-on-your-first-book-expires.aspx
Incredible.
On Tue, 9 Oct 2012 10:42:02 -0700 (PDT), jmk wrote:
> This is definitely old. It only has Exit, Return, Save and Poke options,
> no Printing, no Jumping, no Toolkit.
designing my own "Multiface", long before the MF-1 appeared on the market.
But those days, you couldn't simply start up EAGLE, load a few libraries,
connect some buses and signals, click on "Autoroute" and send the
CAD-/CAM-Files to some service provider.
And the parts were pretty expensive - I remember having paid big bucks for
the inevitable Z80-PIO and the bigger RAM chips to replace the upper 32k
of my Speccy and allow bank switching. Not to speak of the female part
matching the edge connector...
So erasing/burning an E-PROM, designing a PCB AND developing M/C software
to deal with backupping what the Speccy had in its RAM was way out of
reach. Today, you could emulate stuff instead of crashing GENS for the
1000th time - that's how I developed mdv2img, the tool that helped me to
create images from Microdrive cartridges.
Some 25 years ago, not even a singlestepping mode with register display
existed, so it was pretty much trial and error.
> I tried it with Genie and Lifeguard and, sure enough, it can't start them
> when you press the button.
> The picture looks like 1 EPROM, 1 RAM chip (HM6264 = 8K) and possibly a
> load of small logic chips. It's possible that you have the full 8K RAM,
> although I can't tell for sure if all the address lines are attached.
As long as it worked. Did it copy part of the Spectrum's RAM to it's own
RAM to be able to create the BASIC loader plus SCREEN$ and 48K RAM? I
remember my MF-1 corrupting parts of the screen, so it probably couldn't
create a perfect copy of the snapshot.
> I'll have to upgrade the dumping tool to check the size of the RAM.
pretty well documented and lately even the ULA has been reverse engineered
(hats off to Chris Smith, he did an unbelievably cool job - see
http://www.zxdesign.info/book/insideULA.shtml for details!) - but I wasn't
able to get info on how the MF-1 worked.
Probably just generating an NMI, paging out the Speccy's ROM and paging in
the MF-1 ROM and RAM instead. What I didn't know is, that you could trigger
that paging mechanism via software (addresses 9Fh/1Fh). And I never
bothered to investigate how an image is actually restored.
> I think you might be able to burn an EPROM of a newer MF1 version,
> install it and get it to work, as long as the full 8K RAM is wired up.
this probably will have to be stolen out of a museum... ;-)
> ROMS.BIN has the MF128 ROM at offset 0x1E000 (the info is available in
> the DOS version's documents), but it uses different ports from the MF1,
> so you can't swap them.
> The CRC is calculated by a routine in contended memory, so it could be
> made to move a little quicker. ;)
> Regarding digital IDs, when I use Outlook Express on my XP machine, it
> gives me the option to get a digital ID and then goes to a dead link!
that I never felt the urge to look back.
Cheers,
Volker
P.S.: Make sure to read Andrew Pennel's blog about how he wrote his forst
book, "Master Your ZX Microdrive":
http://blogs.msdn.com/b/andypennell/archive/2009/04/27/you-know-you-re-old-when-the-copyright-on-your-first-book-expires.aspx
Incredible.
jmk
Oct 10, 2012, 10:53:07 PM10/10/12
to dr_ve...@freenet.de
On Wednesday, October 10, 2012 3:38:58 PM UTC+1, Volker Bartheld wrote:
> I never disassembled the MF-1 ROM nor did I care much about how it worked. As
> long as it worked. Did it copy part of the Spectrum's RAM to it's own RAM to
> be able to create the BASIC loader plus SCREEN$ and 48K RAM? I remember my MF-
> 1 corrupting parts of the screen, so it probably couldn't create a perfect
> copy of the snapshot.
I checked the ROM of your version and it definitely accesses the full 8K of RAM.
> I never disassembled the MF-1 ROM nor did I care much about how it worked. As
> long as it worked. Did it copy part of the Spectrum's RAM to it's own RAM to
> be able to create the BASIC loader plus SCREEN$ and 48K RAM? I remember my MF-
> 1 corrupting parts of the screen, so it probably couldn't create a perfect
> copy of the snapshot.
> Probably just generating an NMI, paging out the Speccy's ROM and paging in
> the MF-1 ROM and RAM instead. What I didn't know is, that you could trigger
> that paging mechanism via software (addresses 9Fh/1Fh). And I never bothered
> to investigate how an image is actually restored.
There are some unavoidable corruption issues if the stack pointer is pointing at the screen when you press the red button.
> > I'll have to upgrade the dumping tool to check the size of the RAM.
> Are there any schematics of the MF-1 around?
> > I think you might be able to burn an EPROM of a newer MF1 version,
> > install it and get it to work, as long as the full 8K RAM is wired up.
> Indeed. But I still have no E-PROM burner. In the age of GBs of Flash RAM,
> this probably will have to be stolen out of a museum... ;-)
Volker Bartheld
Oct 13, 2012, 4:27:30 AM10/13/12
to
Addendum:
>>> I'll have to upgrade the dumping tool to check the size of the RAM.
>> Are there any schematics of the MF-1 around?
ftp://ftp.worldofspectrum.org/pub/sinclair/technical-docs/Multiface1_Schematics.gif
- however, this document mentions J2, a jumper that acts as a switch to
deactivate the hardware that my device originally never head (but was
retrofitted, of course).
The manual
ftp://ftp.worldofspectrum.org/pub/sinclair/hardware-info/Multiface1_Manual.pdf
also mentions the j)ump option that I wasn't able to locate in the ROM
that came with my copy.
Cheers,
Volker
>>> I'll have to upgrade the dumping tool to check the size of the RAM.
>> Are there any schematics of the MF-1 around?
On Wed, 10 Oct 2012 19:53:07 -0700 (PDT), jmk wrote:
> There's a guy called Cameraman on WOS who says he has schematics of the MF128 and MF3, but I haven't seen them myself.
I just located the MF-1 schematics on
> There's a guy called Cameraman on WOS who says he has schematics of the MF128 and MF3, but I haven't seen them myself.
ftp://ftp.worldofspectrum.org/pub/sinclair/technical-docs/Multiface1_Schematics.gif
- however, this document mentions J2, a jumper that acts as a switch to
deactivate the hardware that my device originally never head (but was
retrofitted, of course).
The manual
ftp://ftp.worldofspectrum.org/pub/sinclair/hardware-info/Multiface1_Manual.pdf
also mentions the j)ump option that I wasn't able to locate in the ROM
that came with my copy.
Cheers,
Volker
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