exxos's Atari, Amiga & retro forum

It's been talked about before.. chips can vanish any time, huge effort to get it working in the first place, nobody will invest the time into such a project. It would just be easier to buy a STE.

EzdineG wrote: 21 Aug 2020 18:06 Does anyone have any insight as to what is necessary for the ROM portion of this upgrade? I can see a somewhat blurry picture of two larger EEPROMS on the high / low sockets, but can't make out anything useful otherwise. Also if anyone knows, can the IDE be disabled but the ROM portion kept?
I'm going to build a few and have a go.
Thanks!

I believe we already spoke about this, but for visibility it doesn't hurt mentioning on here as well that the latest zip has a version of the GAL program with IDE disabled.
The program could quite easily be changed to disable the ROM decoder part as well if someone wants that (in case you have another solution already for ROM decoding, but still want the IDE part of the board)


It's worth mentioning that IDE & ROM is completely separated from the Blitter circuit.
If you only want the Blitter you can skip the majority of the parts on the board and only populate C1,C2,C3,C4,R1,R2 + Blitter :)



For ROM decoding, it assumes your motherboard is jumpered for "1M" roms (to use 2 roms instead of 6) and that you already have some way of actually putting eproms on there.
My motherboard had solder jumpers for this plus a dedicated spot for the missing 74LS11 so I assumed all other motherboards were similar - I've learned that this is not the case :lol:

If your motherboard cannot be put in "1M" mode then you'd need to replicate a similar circuitry or get some 3rd party ROM board that does something like this and intercept the CE from there.
This in itself appears to be a massive topic, but if you are at a place where you are able to run your machine on 1 or 2 eproms instead of the 6 original ROMs then you are well on your way.

The blitter board wants to have the CE signal intended for the eprom(s) as input, and it will return the new replacement CE signal on an output pin. (It cannot decode address 0x00000000 by itself, nor the TOS1.04 address space, which is why it needs that outside CE signal)


Sorry for it not being very user friendly, since there was space on the board I threw on the extra stuff I wanted for my machine without any thoughts on making it easy to configure or all the rest that normally goes with it if it would have been a proper product.

For more polished ROM solutions I would absolutely turn to the @exxos store instead :)

. Best still has blitters for the original line:
http://www.best-electronics-ca.com/custom-i.htm

$40.

The reason the mcu+glue+blitter would be worth putting some effort into is that you can find these chips for less than $10 on e-bay. Not sure what the source of the chips is, but the concept of adapting the ST to use a blitter via a processor daughter card seems to be a technical possibility. Emulating parts of the machine may be a longer term solution, but that road will always end with the question, Why not emulate the entire machine with a raspberry and then stuff the pi inside the case of the ST? Vampire vs TF, etc...

JoeFloyd wrote: 17 Oct 2020 02:33 (...) Emulating parts of the machine may be a longer term solution, but that road will always end with the question, Why not emulate the entire machine with a raspberry and then stuff the pi inside the case of the ST? Vampire vs TF, etc...

I feel that the answers depends whether you own real hardware that would need "just some part replacement" to be in working condition or take advantage from some enhancement (here, having a blitter).

Well anything is possible with the money and resources (within reason :)) but as you may see with some of the projects in flight on this forum and many others in the retro world they take long time to develop and test as most of the people developing are doing this as a hobby and not their day job.

I tend to agree with @exxos for using the GST chip (STE combined MMU, GLUE, BLITTER) it would be easier to just buy an STE.

These chips are not going to be around forever so this is why we have been looking at the BLITTER Re-creatoin project using FPGA. This does start the debate off of FPGAs and then why not putting the whole system in etc and end up with a MiST etc.

However our goal for the BLITTER Re-creation and the Phoenix Sparkalaphobia is to first get it working with existing cores out there to prove the concept and then as we are working in the background - https://www.exxosforum.co.uk/forum/viewt ... 270#p28501 - re-create the exact schematics of the Blitter as the core. This is something @slingshot is interested in and has been working on on some of the other chips.

These chips are custom chips in the first place so by placing an exact schematic matching core in it should be the most accurate re-creation of the original custom chip.

BUT as you can see even this project has taken time.

EDIT: @agranlund board uses the PLCC Socket for the Blitter so the Phoenix Sparkalapobia will fit on the board in place of the socket.

Sorry for my late reply.
Still did not try my board due to some family things.
I have some board left however I don't have spare blitter IC's.
Currently no time for Atari :(

Pm sent oldskool

For me the fun is tinkering and upgrading retro machines. Where’s the fun just buying one of these modern STE machines :D

Yes I can send you one. Currently I have some family related issues which limit my time so I can’t do it immediately.

Dear All,

Had some time to finally install the board.
First time success!!
The Blitter and IDE works. Now I need a TOS upgrade :) (I am currently booting EMUTos from floppy to get IDE support)
I saw that Anders also published a TOS upgrade on Github so probably will order that PCB soon.
But first I need to play some Giana sisters from HD with Blitter scrolling and Scummvm.

Of course, I can only highly recommend EmuTOS - not only because of its built-in IDE driver in the 256k version. But I know that some people do not want to upgrade their machines with a 256k ROM decoder, for different reasons. So, I wrote a patch to allow TOS 1.04 to boot from IDE. You will still need a hard disk driver such as HDDRIVER or AHDI, though.

While this was developed as a Christmas gift last year for Lightning ST customers, I decided to make it available to everyone: https://github.com/czietz/ideboot. Obviously, for legal reasons I cannot provide the final ROM image (that you could burn into your 6 EPROMs), so this is distributed as a TOS patch to be applied the user.