32768 color dual Shifter ST mod - schematics lost?

[mrbombermillzy]

The STF I have is the donor machine, and I already have removed some key parts that make it unable to run

You mean for this project??!! I guess you are short of a shifter or two?

Are you at ease with soldering ? I can send you one PCB when I receive them.

Thank you, but unfortunately, not at all, hence the offer to help with what I CAN do!

The closest machine I have to a 'regular' STF/M here is a Mega ST, which doesnt really help from the software side, as the code I'm going to be writing is targetted at (currently) non existent HW, so I may just as well write from the TT anyway. (Or Hatari fast TT emulation, as the code isn't timing critical).

Fair enough, if there's no rush then, I will send you the code at some point for when you have a working machine with the board in.

[sporniket]

The STF I have is the donor machine, and I already have removed some key parts that make it unable to run

You mean for this project??!!

No, it's my donor machine for the H5, don't worry. But the H5 is not advanced enough to run, and the donor machine is dismantled enough to not run anymore.

Are you at ease with soldering ? I can send you one PCB when I receive them.

Thank you, but unfortunately, not at all, hence the offer to help with what I CAN do!

The closest machine I have to a 'regular' STF/M here is a Mega ST, which doesnt really help from the software side, as the code I'm going to be writing is targetted at (currently) non existent HW, so I may just as well write from the TT anyway. (Or Hatari fast TT emulation, as the code isn't timing critical).

Fair enough, if there's no rush then, I will send you the code at some point for when you have a working machine with the board in.

Well, It is possible for me to assemble one for you ; I have to buy the components first though, so I will ask to share the cost, and there will be no shifter included (you will have to get them yourself)

[mrbombermillzy]

Well, It is possible for me to assemble one for you ; I have to buy the components first though, so I will ask to share the cost, and there will be no shifter included (you will have to get them yourself)

I wasn't going to ask that of you, but as you have kindly offered, that would be absolutely fantastic!

Of course, I will pay for any costs required. Just to get this proof of concept operational is my reward!

I guess this is a good time to ask (anyone lurking on this thread too) if there are any variations of ST/F/M/Mega shifter part no.s with any known timing characteristics which differ from one another? (In which case, I will try to get a matching pair).

[sporniket]

Of course, I will pay for any costs required. Just to get this proof of concept operational is my reward!

I won't order before next month, so I will tell you how much at that time. (Anyway I have first to receive the pcb and check the fitting)

I guess this is a good time to ask (anyone lurking on this thread too) if there are any variations of ST/F/M/Mega shifter part no.s with any known timing characteristics which differ from one another? (In which case, I will try to get a matching pair).

Good question, I guess that having two of the same kind is better.

[mrbombermillzy]

I won't order before next month, so I will tell you how much at that time. (Anyway I have first to receive the pcb and check the fitting)

No problem. Let me know when you are ready to order.
Also, good point about fitting. I'd better dig the Mega out and check there's not too much clutter around the shifter!

I guess this is a good time to ask (anyone lurking on this thread too) if there are any variations of ST/F/M/Mega shifter part no.s with any known timing characteristics which differ from one another? (In which case, I will try to get a matching pair).

Good question, I guess that having two of the same kind is better.

I think it's more a thing with the ST blitter, but I'm not sure if there are any different ST shifters. (I will check that out in the meantime anyway and try to grab myself an identical one if there is).

[mrbombermillzy]

According to the Best catalog, there are 4 ST/Mega shifter part nos:

CO25914
CO70713
CO7013
I10356

EDIT: Also, according to Ijor here: https://www.atari-forum.com/viewtopic.php?f=16&t=33962

There are also (at least) 3 revisions of the CO25914; -20, -38 and -38A, which are not completely compatible with each other.


Will have to see what's in the Mega then and try to match that up.

[sporniket]

@mrbombermillzy there will be one thing to do before installing the mod :

«Additionally, jumpers are installed across
each of three 3.6K ohm resistors on the motherboard.
These resistors are easily traced from the Shifter
socket pins 21, 24, and 27.»

I hope that is ok with you.

[mrbombermillzy]

@mrbombermillzy there will be one thing to do before installing the mod :

«Additionally, jumpers are installed across
each of three 3.6K ohm resistors on the motherboard.
These resistors are easily traced from the Shifter
socket pins 21, 24, and 27.»

I hope that is ok with you.

If it's something simple, (like 3 jumpers) I can get it done by someone who lives near me. No worries.

[sporniket]

great

[mrbombermillzy]

According to the Best catalog, there are 4 ST/Mega shifter part nos:

CO25914
CO70713
CO7013
I10356

EDIT: Also, according to Ijor here: https://www.atari-forum.com/viewtopic.php?f=16&t=33962

There are also (at least) 3 revisions of the CO25914; -20, -38 and -38A, which are not completely compatible with each other.


Will have to see what's in the Mega then and try to match that up.

P1040129.JPG (116.92 KiB) Viewed 2879 times

It seems I have the IMP chips, including shifter p/n: CO70713-002, so if anyone has one of these going spare they wouldnt mind selling, Id be very grateful!

Alternatively, a matching pair of other shifters will do.

As a last resort, I suppose I could use 2 odd shifters. As long as I dont do anything drastic (like running scene demos) they should play nicely, but this is far from ideal.