IIfx + Mac286

[moonferret]

Hi Folks!

Just picked up a nice Mac IIFx with an AST Mac286 board set installed. However, I'm having trouble getting the card to run. Tried V2 & V3 of the AST drivers from the Mac Driver Museum, System 6 & System 7 and with 32Bit addressing switched off. Keep getting bus errors though. Anybody got any suggestions? Is the board even compatible with a IIfx?

Cheers,

Dave

 

[Trash80toHP_Mini]

In the WikiPedia link that popped up in your post, it sure sounds like the Card was supported through the IIfx period.

That said, the Mac IIfx had very funky I/O subsystems utilizing Apple II Procs (6502s?) to speed throughput. From the sound of the Mac286's use of Mac II I/O ports such as both the modem and printer ports as PC Serial Ports and the Superdrive as an IBM 1.44 FDD, my best guess is that its drivers die a brutal and ugly death when faced with the Mac IIfx Architecture.

 

[moonferret]

Ok, a little progress. It seems that the Mac286 board will work on all Mac II series machines but when it comes to the IIfx, system must be running in 24bit mode and the serial ports set to compatible, not fast. The serial port mode can apparently be changed in a control panel. Now, all I need to do is find out what control panel this is!

 

[Trash80toHP_Mini]

Good job so far! :approve:

 

[IPalindromeI]

Memory allows you to control 24 or 32 bit mode, and maybe Serial Switch could allow for compatible serial? Never tried the last one.

 

[moonferret]

Sorted! Downloaded 'Serial Switch' control panel from Apple's site and set the mode to compatible. Mac286 software then loaded without crashing but all I got was a spinning hour glass and menu options were disabled. Couldn't find any other software options to change so I thought I'd pull the cards to see if there were any jumpers to change. Nothing obvious but I did notice a nice shiny gold maths co-processor....8087....Hmm...286 CPU! Pulled the 8087 and tried again. Success!

So, if anybody else is trying to run an AST Mac286 on a IIfx, you need to be running in 24bit addressing, Serial ports set to compatible and make sure nobody has stuffed the wrong co-processor in!

 

[jruschme]

Out of curiousity, which version do you have- two-board AST, two-board Orange or single-board Orange?

 

[moonferret]

Its the two board AST. Would have liked to put some more RAM on it but it seems that it won't accept more than 1Mb. In fact, it only shows 640k on boot up. Ahh well, no Windows then

 

[IPalindromeI]

That's just DOS' conventional memory limit... With a DOS extender it will see more. However, 286 processors do not implement protected mode as a 386 does, so modern DOS stuff won't run.

 

[moonferret]

The board has a similar POST screen like you would see on a real PC. It counts up the base ram to 640k but does not count any expanded / extended RAM which leads me to believe it simply does not recognise the extra 384k (At least not without a firmware / SW update) Anyway, apparently 640k is enough for anybody!

 

[bbraun]

I've got one of these boards in a IIx, and it runs the 286 version of windows2 OK.

The early boards (like the ones we've got) don't seem to handle >640k. Newer versions of the boards supposedly handle up to 4MB. Oh well, it is still kinda cool though.

 

[olePigeon]

Oooo, nice score.