8086 upgrade/conversion on Mega ST?

[rasch_C]

My buddy received this Mega ST in where he works. It has this board in place of the CPU. I do not know much about Atari computers, but it appears to be maybe some sort of 8086 DOS conversion? Can someone identify?

 

Thank you

-Allen

[Fadest]

It is an expansion board that were used by emulator (PC Ditto or Supercharger probably) on the Mega ST.

Thé 68000 is still here, probably hidden under the board,

[Almerian]

 

 

My buddy received this Mega ST in where he works. It has this board in place of the CPU. I do not know much about Atari computers, but it appears to be maybe some sort of 8086 DOS conversion? Can someone identify?

Thank you
-Allen

If my memory is correct this is the PC Speed. It adds PC compatibility.

[tschak909]

I'm guessing the PC majority of the PC compatibility is in software (8259 emulation etc), as the only thing here is a CPU and some bus arbitration logic.

 

-Thom

[guus.assmann]

Hello,

 

This is indeed a PC speed.

It was faster than the original PC, because the Atari did the I/O and screen.

It's very much compatible with a PC.

Made by Sack. Needs a disk to drive it and of course a Dos3.0 or so.

Later, a 286 and I think also a 386 were made.

 

BR/

Guus

 

PC Ditto was a software emulator.

Supercharger is a PC connected to the Atari with the DMA.

[rasch_C]

Pretty interesting. How commonly was this done back in the day? How do you switch it into PC/DOS mode (what disk?)

 

-Allen

[MrMaddog]

I rememeber wanting to get one for my STe cause of all the DOS-based programs my college was using at the time. But the local Atari dealer talked me out of it saying that caused problems in the sandwich style cases where the 68K stopped working.

 

Well knowing back then what i know now I could have gotten a used PC, make an AUTOEXE.BAT file tell DOS to send all text output to the serial port, use a null modem cable and run ANSITerm to use the ST as a terminal for the PC.

[guus.assmann]

Hello,

 

As more often, Google is your friend: http://www.atarimania.com/utility-atari-st-pc-speed_23201.html

I searched for "Atari ST PCSpeed and it was the first hit....

 

DRDos worked very well on this emulator.

And there's a 386 version, called "AT Once" in both an ST and MegaSTE version.

 

BR/

Guus Assmann

Edited March 22, 2018 by guus.assmann

[rasch_C]

Hello,

 

As more often, Google is your friend: http://www.atarimania.com/utility-atari-st-pc-speed_23201.html

I searched for "Atari ST PCSpeed and it was the first hit....

 

DRDos worked very well on this emulator.

And there's a 386 version, called "AT Once" in both an ST and MegaSTE version.

 

BR/

Guus Assmann

Yeah, I'll have to read Atarimania some more on this. My Googling for Atari "PC Speed" landed me here: http://wiki.newtosworld.de/index.php?title=PC-Speed which confirms visually what it is.

 

Thank you,

-Allen