EPROM's for A1200/A4000
Lars S. Jessen
Who can tell me what type of EPROM is pin compatible with the
kickstart ROM's in an A1200/A4000?
Will an 27C2048 work?
Is the A1200/A4000 cabable of addressing 2*512kB ROMs instead of
the 2*256kB ROMs?
Regards.
Lars Jessen
MARK OVERBAUGH
said, I have done a small adapter to use a pair of 27c020 EPROMS in the
single kickstart socket of the 500/2000. Its much easier to program 8
bit EPROMS than 16-bit ones, since the cheap EPROM burners need adaptors
for the latter. My design also allows you to have a standard KS rom in
another socket, and switch between the two. Might be of some use.
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A4000/040 (Commodore) 2mchip/16mfast
270mb IDE HD 4x ATAPI CDROM
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Tilo Hacke
> said, I have done a small adapter to use a pair of 27c020 EPROMS in the
> single kickstart socket of the 500/2000. Its much easier to program 8
> bit EPROMS than 16-bit ones, since the cheap EPROM burners need adaptors
> for the latter. My design also allows you to have a standard KS rom in
> another socket, and switch between the two. Might be of some use.
There are pin compatible EPROMs: 27C200 (256kB)/27C400(512kB)
But they are very rare and expensive (about 25 $), since they always
were used for development only. I bought 26 of them a few years ago
when they were available for 10 $.
Tilo Hacke
Dave Clarke
'Re: EPROM's for A1200/A4000':
>AFAIK there are no pin compatible EPROMS for the kickstart sockets. That
>said, I have done a small adapter to use a pair of 27c020 EPROMS in the
>single kickstart socket of the 500/2000. Its much easier to program 8
>bit EPROMS than 16-bit ones, since the cheap EPROM burners need adaptors
>for the latter. My design also allows you to have a standard KS rom in
>another socket, and switch between the two. Might be of some use.
27c400 from AMD are pin compatible with A4k, A3k, A2k, A500, A600 ROMs.
A1200 seems to have used different ROMs, (at least in the ones I've had a
look at), with which the 27c4096 is compatible.
Dave
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Ross Vumbaca
MARK OVERBAUGH wrote:
>
> AFAIK there are no pin compatible EPROMS for the kickstart sockets. That
> said, I have done a small adapter to use a pair of 27c020 EPROMS in the
> single kickstart socket of the 500/2000. Its much easier to program 8
> bit EPROMS than 16-bit ones, since the cheap EPROM burners need adaptors
> for the latter. My design also allows you to have a standard KS rom in
> another socket, and switch between the two. Might be of some use.
I think the 27c400 are pin compatible.
Anyway, have you put your design on Aminet or something? ;-)
Regards,
Ross..
Gl...@canit.se
+Dave Clarke <4...@connexus.net.au> wrote
>27c400 from AMD are pin compatible with A4k, A3k, A2k, A500, A600 ROMs.
>A1200 seems to have used different ROMs, (at least in the ones I've had a
>look at), with which the 27c4096 is compatible.
Are you sure ? that's a very common EPROM.. got a bunch of them laying
in the shelf here :)
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Ross Vumbaca
Gene Heskett wrote:
> > Dave Clarke wrote:
> >27c400 from AMD are pin compatible with A4k, A3k, A2k, A500, A600 ROMs.
>> >Are you sure ? that's a very common EPROM.. got a bunch of them laying
>> >in the shelf here :)
> Nope, the footprint is different, not to mention I *think* thats only an
> 8 bit wide chip. One of the oddities of the 27c400 is that it has a
> mode pin, which allows the programmers to treat it as an 8 bit chip for
> programming purposes, but then read it 16 bits wide. 2 of them in the
> 1200/3000/4000 allow a full 32 bit path to kickstart, whereas you must
> use some sort of a fastrom proggy to get that effect on a 500/1000/2000.
So why is it a problem then - if they are written at 8 bits but are read
at 16 bits wide then they should be fine..!
I don't know what you mean by the footprint though - shape?
Regards,
Ross..
MARK OVERBAUGH
thinking of 27c040?
Jack O Lantern
I got a shipment of 3.1 "ROMs" today from Germany today and the ones for
the 500/600/2000 were EPROMs or maybe EEPROMs. I don't have a guide to
look up the part #'s.
Here's the info on the chips:
MX
27C4100DC - 12
1A1134
VPP=12.5V
TAIWAN
P992832
Anybody want to look them up?
I noticed they weren't ordinary ROMs when I went to peel off the "OS 3.1"
sticker-- I figured there's little point in helping keep the chip warm.
That's when I noticed the little window :-) and I covered it back up.
Ross Vumbaca
Gene Heskett wrote:
> >> >27c400 from AMD are pin compatible with A4k, A3k, A2k, A500, A600 ROMs.
> >> Nope, the footprint is different, not to mention I *think* thats only an
> >> 8 bit wide chip. One of the oddities of the 27c400 is that it has a
> >> mode pin, which allows the programmers to treat it as an 8 bit chip for
> >> programming purposes, but then read it 16 bits wide. 2 of them in the
> >> 1200/3000/4000 allow a full 32 bit path to kickstart, whereas you must
> >> use some sort of a fastrom proggy to get that effect on a 500/1000/2000.
> >So why is it a problem then - if they are written at 8 bits but are read
> >at 16 bits wide then they should be fine..!
> _IIRC_ the 27c4096 is only an 8 bit wide chip. And footprint refers to
> pin function vs pin number. A pin thats data on one, and address on the
> other, makes it kinda hard to just 'plug them in'.
I see.... I assume your also referring to the 27c400 as having a
different footprint (for A500/A600/etc use).
Is there any way to know a EPROM by looking at it? These two 3.1 OS
chips (for a3k) that are new and from Amiga Int. are unlike the old C=
ones. They have no chip manufacturer logo (chip is completely covered
with an Amiga sticker) and there is a "gray" layer visible. Similar to
those ROMs in the A590 I have, those A590 ROMs had "C64...." printed on
them, which was part of a code that meant they were UV EPROM's.. - Could
these new AInt. ROM's be EPROM's? (Or am I completely off the planet..?
;-) )
Regards,
Ross..
Gl...@canit.se
+MARK OVERBAUGH <mover...@home.com> wrote
>27c4096 should be 16 bits wide (27c1024 is 16 bit). Perhaps you were
>thinking of 27c040?
I seem to remember that 27c4096 and 27c040 are compatible ? just that AMD calls
them 27c4096 and TMS calls their 27c040 ?
Eventually 27c4002 (SGS-thomson) would be compatible too.. I have all my EPROM
papers at work..
Allan Duncan
The mob who's logo is "MX" is Macronix, and are about the last world
manufacturer of this pinout.
They also do a windowless version that I have had, with 3.1 inside.
I looked into getting some a while back but I would need to do an import
with large minimum quantities.
Allan Duncan a.du...@trl.telstra.com.au (+613) 9253 6708, Fax 9253 6776
Infrastructure Program - Core Network Architecture & Performance Section
Telstra Research Labs, Box 249 Rosebank MDC
Clayton, Victoria, 3169, Australia