TommyPROM/docs/_docs/ref-300-2316-2332-roms.md

4.2 KiB

title permalink exerpt
2316, 2332, and 2364 ROMs /docs/2316-roms 2316, 2332, and 2364 Read Only Memory

2316, 2332, and 2364 Mask-Programmable Read-only Memory

The 2316 is a 2Kx8 mask-programmable ROM made by Commodore. Intel made a version called the 2316E. There were also 4K and 8K versions produced as the 2332 and 2364. These chips were used by a wide variety of computers in the late 1970s and early 1980s, including products from Commodore, Atari, Ohio Scientific, Radio Shack, and others.

Compatibility with UV EPROMs

The 2316, 2332 and 2364 ROMs are somewhat unique because they have Chip Select signals that are configured when the data is mask-programmed. Manufacturers could order a 2316 configured with any of its three Chip Select signals as either active-high or active-low.

This causes a bit of confusion, because the datasheets state that the chips are compatible with standard EPROMs, but they should really state that the chips can be compatible, depending on the configuration selected. For example, a 2316 is only compatible with a 2716 if CS1 and CS2 are configured active-low and CS3 is configured active-high. Otherwise, some signals will need to be inverted to swap out a 23 serial chip with a more standard EPROM.

Some systems will contain multiple 23xx chips with the Chip Selects configured the same and others will configure each chip differently. For example, some 8K Atari cartridges use two 2332 chips and will invert one of the Chip Selects so that either chip can be selected with a single address line to differentiate them. If the chips are removed from the cartridge, they would need different Chip Selecct wiring to read their data.

Reading 23xx chips with TommyPROM

A TommyPROM programmer can be constructed with an Arduino to read 2316 ROM chips. The code will scan the ROM to determine the correct Chip Select settings, so no wiring changes or inverters are needed when switching chips of the same type.

To use TommyPROM with 2316 chips, perform the following steps:

  • Connect the Arduino data bus lines (D2..D9) to the ROM data lines.
  • Connect the shift register address lines to the ROM address lines.
  • Connect Arduino A2 (WE) to the ROM's CS3 on pin 21.
  • Connect Arduino A1 (CE) to the ROM's CS2 on pin 18.
  • Connect Arduino A0 (OE) to the ROM's CS1 on pin 20.
  • Compile the TommyPROM code with PROM_IS_23 enabled

When running the TommyPROM software, first use the Unlock command to scan the chip. This should detect the correct configuration of the chip select lines. After the scan us complete, the Dump or Read command can be used to read the data.

The 2332 only has two chip selects, so pin 21 should instead be connected to the shift registers A11 and the Arduino Pin A2 left unconncted. For the 2364, pin 21 connects to A12 and pin 18 connects to A11.

23xx Chips and Configurations

Model Type CS3 CS2 CS1 Tested Notes
UK101
MONUK02 2316 x H H Y
BASUK01 2316 x H H Y
BASUK02 2316 x H H Y
BASUK03 2316 x H H Y
BASUK04 2316 x H H Y
Commodore 64
901225-01 2332 - N Character ROM
901226-01 2364 - - N Basic
901227-03 2364 - - N Kernel
Commodore VIC 20
901460-03 2332 - L L N Character ROM
901486-01 2364 - - N Basic
901486-06 2364 - - N Kernel
Commodore 1451
325302-01 2364 - - N DOS
901229-05 2364 - - N Kernel
TRS-80 Model 1
ROM A 2364 - - N
ROM B 2332 - N
Apple II
Ohio Scientific SuperBoard
2316
Atari 400 and 800

References

Commodore 64

VIC 20 Character ROM

2532 vs 2732

2332 vs 2532