6502.org

Posted: **Tue Jul 04, 2006 11:30 am**

Hello. This is my first post to this forum so I hope I'm not asking stupid questons and wasting folks time.

I have my original 1977 old rom PET up and working and I'm toying with expanding the on-board 8K memory. On the expansion port I currently have installed a PAICs Programmers Toolkit. I cannot tell what type of ROM this board contains, but it does appear to be a Synertek chip, and my best guess is that it's a SY2136B. The board has a slot for another 2K chip and I'd like to try sliding a compatible RAM into here. Anyway, if anyone out there knows what chip I actually do have on the Toolkit board I'd appreciate the info.

Markings on the ROM are: 7946E C48178 TOFF6 79

Many thanks, Darren.

Posted: **Wed Jul 05, 2006 3:40 pm**

Not a time waste, and could it possibly be a 2316 type ROM? that number makes more sense as a 2K type, 8 by 2K being 16 kbits.

Posted: **Thu Jul 06, 2006 5:27 pm**

The original Commodore 64 used 2364 ROMs for the 8K kernel and 8K BASIC software. I wonder if the pinouts of those ROMs are compatible with the 2316, just as the 2764 is backward compatible with the 2716? If so, you can find the schematics for the C64 online via Google.

Posted: **Thu Jul 06, 2006 6:09 pm**

Code: Select all

2316 ROM

Pin     Pin
 
 1  A7   24  VCC
 2  A6   23  A8
 3  A5   22  A9
 4  A4   21  CS- (NC on early chips)
 5  A3   20  CS-
 6  A2   19  A10
 7  A1   18  CS
 8  A0   17  D7
 9  D0   16  D6
 10 D1   15  D5
 11 D2   14  D4
 12 GND  13  D3

Source here

Posted: **Tue Jul 11, 2006 7:09 am**

Gday again,

Thanks for the feedabck - my 2136 reference was an unfortunate typo. I have since done some further checking and the Toolkit suggests that New ROM versions of the PET will have the chip plugged directly onto a spare slot on the motherboard....further digging finds that the New ROM versions used 2316 chips - so I guess mystery solved.

Thanks for all the help folks - next task is to learn assembler (so I may be back). Once again, thanks.

Posted: **Tue Jul 11, 2006 7:20 pm**

Cmon back anytime. We're all in the 6502 together

6502.org

PET Programmers Toolkit

PET Programmers Toolkit