Jeri board and extra things

From: Frank Kontros (
Date: 2001-05-02 00:29:03

Hello all,

>> I'm curious how many people would be interested in
>> an entire motherboard replacement instead?  Maybe with
>> the option to plug original chips into it?

If it will drop down the overall price of the board and would
have more i/o connections, why not? Today I can still order
orignal C= chips like 6502, 6522, 6510, 6526, 6581, 8580. Even
desolder old chips from "dead boards" not a big work.

PD> If I'm replacing the mobo, I think I'll just setup my
PD> Super-64 in a PC tower case. The new board ought to be
PD> designed with this in mind.

Right. Form factor of the PCB shouldn't be designed for C64 case.

PD>  Also, there should be a
PD> connector for a PC keyboard and included logic to
PD> decode PC keypresses as equivalent C-64 keys. Might be
PD> a good idea to allow people to customize the decoding
PD> matrix too, perhaps by writing the new matrix into a
PD> PRAM-type area? 

Optional. C128 keyboards can be used or rewired PC keyboards
can be also used.

PD> Make the KERNAL customizeable. Maybe have it copied to
PD> RAM on power-up. Then implement KERNAL patches by
PD> loading them from the PRAM-type area. Now I can
PD> customize my KERNAL without loading from disk or
PD> burning EPROMs  :)

Right idea. Today's 2Mbit FLASH PROMs with price and
capacity are enough for C=. Can be also omitted and user
programmed, but FLASH programming needs a prog. device.

PD> The cassette port can definitely be ditched. Same
PD> thing with the RF output.

At least the power lines can be wired to same-type PCB connector for

PD> The User port is not essential, but would be nice for
PD> connecting audio/video digitizers and printer devices
PD> which already exist and require it.

USER PORT is necessary for C64-PC connection, centronics printers,

PD> Slots are very desireable.

Right. At least 2 preferable.

PD> 65816 socket is a MUST so we can write sophisticated
PD> new apps to take advantage of the new hardware. It
PD> would also ease the burden of developers who are
PD> willing to port their SuperCPU apps.

Not sure about this. If the user want compatibility then remove 65816
and insert 6502? Or dual-CPU-socketed PCB? One for 6502 and
one for 65816? Would be very nice, but little comlicated I think.

PD> Other desireable features include ETHERNET, IDE, USB,
PD> SCSI and true RS-232.

Ethernet and USB are good things. Although, there are many USB->Ethernet
converters today in the market. BTW, I can't found so many docs about
programming many USB devices on the manufacturers site. Probably Linux also
lacks USB devs because manufacturers sells devices only for winXX?

IDE and SCSI is not needed inside C64/128. Why complicate the HW
inside C= and lost compatibility, when from the first time C= used
peripherals as storage units. I think it's better to connect IDE
(or SCSI) HDD or CD-ROM drive to 1541 (or equivalent) electronics,
patch kernal and forget about incompatibility. (At least easier than
write a new incompatible OS-kernal for C64 (like IDE64)). Parallel
cables (or Jiffy-DOS like routines) can be used to speed up transfer
between peripherals and C64 and thats all. (100% CMD command set I
don't mentioned but have in mind)

115K or faster 16550A is also good thing. Probably a socket for it
enough for most of users. If they desire to use it, simply buy
(or desolder) one and insert it (with buffers of course). The price can
be cut down in such way.

In case of entire MB replacement, extra memory (with DMA controller)
or socket for extra RAM *very* preferable.

For price-sensitive users I think a blank (socketed) MB with Jeri's
VGA/VIC-II/VDC? controller+FLASH ROM and necessary I/O connectors is the
best-buy. (I have at least many C= chips laying around waiting
for "good-days".)

Best regards,

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