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carlsson
July 18th, 2006, 02:59 AM
Does anyone know the base address of the system ROM on a PET/CBM 8032, and the command(s) to access it?

Here is a little bit of info (http://www.baltissen.org/htm/ec8032k.htm) about the memory map, but nothing about the commands
You can find more detailed memory maps here:
http://www.zimmers.net/anonftp/pub/cbm/maps/index.html

Exactly what does your friend want to access out of the ROMs? Commodore Basic has PEEK, POKE, SYS and the occasional WAIT, which functions like a PEEK loop. Working against a ROM address, only PEEK and SYS make sense.

The reset vector on a 8032 is $FD16, or SYS 64790 in decimal.

Terry Yager
July 18th, 2006, 09:22 AM
The 8032 that I sold him a while back came with some kinda ROM expander, consisting of a daughterboard that jacks into the ROM socket, while the system ROM is moved onto the db, along with three other ROMs. There's a 4-position sliding switch, which presumably coresponds to each of the four sockets. Problem is, neither of us know how to use it, being unfamilliar with C= BASIC. My best guess is that you would set the switch, then put in a CALL to the address of the ROM. That's the way it would be done on some other machines I know, but C= BASIC doesn't seem to have a CALL command, So I'm just wondering what the command might be to execute an M/L program at a certain address.

--T

kb2syd
July 18th, 2006, 09:30 AM
We had machines similar to that in high school (way back in 1983). They were 8032s with an external switch exactly as you described. For us, each switch selected a different language. Ours had the standard pet basic, and then a different structured basic, pascal and fortran. I think this was a University of Waterloo add on.

For us, you turned the machine off, selected the rom bank via the switch, and then turned the machine back on.

Terry Yager
July 18th, 2006, 09:52 AM
We had machines similar to that in high school (way back in 1983). They were 8032s with an external switch exactly as you described. For us, each switch selected a different language. Ours had the standard pet basic, and then a different structured basic, pascal and fortran. I think this was a University of Waterloo add on.

For us, you turned the machine off, selected the rom bank via the switch, and then turned the machine back on.

Of the ROMs on the device, one was obviously the system ROM, and the only other one that was labeled was 'SpellMaster' or similar, so I'm guessing that one or more of the others were for word processing.

I tried setting the switch and turning on the machine, but in all 4 positions, it still came up to a BASIC 4.0 prompt, and functioned as normal.

--T

carlsson
July 18th, 2006, 01:05 PM
The equivalent to CALL is SYS. You give a number, typically the start address of the ROM you want to start. However, if there is no executable code at that address, the machine will freeze or go into the system monitor if it has one.

Maybe the other ROMs were poorly seated? From what I know, PETs have several sockets on the motherboard for system and application ROMs, so maybe the daughterboard went into a position for the application ROMs rather than one of the system ROMs. That is unless you looked up the part number to verify which chip or socket it was.

Ask your friend to open the machine, check for a number next to the socket (U19 or similar) and write down the numbers of the ROM chips on the daughterboard, and it will be easier for other people to identify what it is and how to use it. Perhaps a detail picture of the interesting part of the motherboard will help too.

Terry Yager
July 18th, 2006, 01:31 PM
I've directed him to this thread. Hopefully, he'll read this for himself.

--T

carlsson
July 18th, 2006, 04:02 PM
And if the issue can not be solved, I have another trick up my sleeve (called mailing list). :-)

Bill_Loguidice
July 19th, 2006, 06:58 AM
We had machines similar to that in high school (way back in 1983). They were 8032s with an external switch exactly as you described. For us, each switch selected a different language. Ours had the standard pet basic, and then a different structured basic, pascal and fortran. I think this was a University of Waterloo add on.

For us, you turned the machine off, selected the rom bank via the switch, and then turned the machine back on.

8032's could be upgraded to SuperPET's, aka SP9000, which was a stand-alone machine. I have two of them. Basically a SuperPET has two separate connected motherboards, extra memory and was primarily designed to act as a "Micromainframe" and programming language education machine (the rocker switch on the right side changed between CPU's and various read/write modes). It's truly a fascinating system, but requires a disk drive (I have the dual drive 8050) to make use of the extra languages, since they come on disk.

Here's a pic (the keyboard "overlay" is just sitting on top there): http://www.billandchristina.com/vgamecomp/images/collection5/ar5/DSC02484.JPG

And a pic of the disk drive unit: http://www.billandchristina.com/vgamecomp/images/collection5/ar5/DSC02624.JPG

kb2syd
July 19th, 2006, 08:08 AM
It's truly a fascinating system, but requires a disk drive (I have the dual drive 8050) to make use of the extra languages, since they come on disk.

Going from memory, we used several "shared" disk drives. I think they were shared using the GPIB interface. Does this sound correct/possible? It's been 20+ years so the memory is a little hazy.

Bill_Loguidice
July 19th, 2006, 08:12 AM
Going from memory, we used several "shared" disk drives. I think they were shared using the GPIB interface. Does this sound correct/possible? It's been 20+ years so the memory is a little hazy.

I know nothing about GPIB, but it was absolutely possible to create a PET network, so I wouldn't be surprised. It would have made a lot more sense back then to do that rather than get expensive and super bulky disk units for everyone, particularly in a network's then-natural environment of a classroom.