Jiffydos 6.01 Question on C128-DCR

[David Hoelzer]

Hiya!

I just purchased a ROM image set from RetroInnovations (I have emailed them and am still waiting for a response) for the 128-DCR. The problem I have is that they come with absolutely no documentation.

I'm assuming that the JiffyDOS_C128DCR_6.01.bin and C64_6.01.bin end up together in an EPROM in U32, but how do they get put together? Or do they go somewhere else?

I found various opinions about using 27256 or 27512 chips... I've actually tried both with one or both images on them, but cannot seem to find a combination that works. How *exactly* do these images need to be combined to have a working 128?

Thanks!

[Anssi Saari]

David Hoelzer <cyberdef...@gmail.com> writes:

> Hiya!
>
> I just purchased a ROM image set from RetroInnovations (I have emailed
> them and am still waiting for a response) for the 128-DCR. The
> problem I have is that they come with absolutely no documentation.
>
> I'm assuming that the JiffyDOS_C128DCR_6.01.bin and C64_6.01.bin end
> up together in an EPROM in U32, but how do they get put together? Or
> do they go somewhere else?

Looks to me U32 in a 128DCR should have the C64 basic and C64 and C128
kernals all in one chip. From the description on RetroInnovations it
seems like they ship only the kernals in separate files? So if your
JiffyDOS_C128DCR_6.01.bin is 16 kB and C64_6.01.bin is 8 kB then that
would seem to be the case.

So you'll need to combine a C64 basic with those two kernals for one 32
kB image. From a quick look at the C128DCR schematic and PRG it looks
like the high half of the ROM has the C128 kernal so the low half should
have the basic and C64 kernal. I don't know which order but I'd guess
basic first since it's first in the C64 memory map. Could be the other
way around too of course. Still, only two combinations to try...

[Jim Brain]

On 6/16/2021 9:01 AM, David Hoelzer wrote:
> Hiya!
>
> I just purchased a ROM image set from RetroInnovations (I have emailed them and am still waiting for a response) for the 128-DCR. The problem I have is that they come with absolutely no documentation.

I have to disagree with that statement. Every ZIP file, including the
C128DCR file comes with a file called: ROM Creation README.txt. In it,
it says:

ROM creation requires a EPROM/FLASH/EEPROM programmer and suitable stock:
(EPROM, EEPROM, FLASH). It is beyond the scope of this document to explain
programming steps. Consult your user manual for programming information.

The non-JiffyDOS CBM files can be found at
ftp://www.zimmers.net/pub/cbm/firmware/drives/new/

The non-JiffyDOS non-CBM files are typically available at Zimmers as well,
but can also be read from your existing drive ROM(s)

Jim Brain
RETRO Innovations
--------------------------------------------------------------------------

Switched C128/C128DCR KERNAL ROM (32kB)
basic.901226-01.bin
kernal.901227-03.bin
kernal.318020-05.bin
basic.901226-01.bin
JiffyDOS_C64_6.01.bin
JiffyDOS_C128DCR_6.01.bin

I will admit the size is wrong (a switched unit requires 64kB EPROMs,
but everything else is there.

Jim
--
Jim Brain, br...@jbrain.com
RETRO Innovations: Contemporary Gear for Classic Systems
www.go4retro.com