Overview
Some older Vectorbeam and Cinematronics CPU boards were wired for factory mask programmed ROMs and user programmed PROMs rather than 2716 EPROMs. When these parts need to be replaced, the board will not use regular EPROMs without additional work.
Installation
There are two options for replacing masked ROMs: use two modified 2532 EPROMs installed into the CPU, or use two standard 2732 EPROMs installed into the Cinematronics EPROM PCB. For either, new binaries combining the ROMs in the P & R sockets and the T & U sockets must be used. See below to download ready-made copies of these images.
A 2004 post by Matt Rossiter details the solution using 2532 EPROMs. The combined images are burnt to two 2532 EPROMs and pin 21 is bent outward on each. Then, jumper wires are soldered between pin 21 and 24. This causes pin 21 to be held active high rather than active low. The ROMs are then ready to be installed in P7 & T7 on the CPU board and power applied.
Using the Cinematronics EPROM PCB, the images are burnt onto two 2732 EPROMs. These EPROMs are installed in the daugherboard in sockets P7 and T7. After properly setting the jumpers on the board for this application, the board is ready to be powered up.
Downloads to Replace Masked ROMs
Below are download links to combined ROMs. I have tested Space Wars, Speed Freak and Tailgunner and confirmed they would run on my Tailgunner PCB. Warrior was tested and confirmed working on a Warrior PCB with JMI instlled. The images are ready for burning to either 2532 or 2732 EPROMs depending on your choice of installation.
Space War(s)
Speed Freak
Tailgunner
Warrior
I'm compiling information below about the masked ROMs and PROMs used in Cinematronics and Vectorbeam hardware:
| Factory Mask Programmed ROMS and User Programmed PROMS | ||||
|---|---|---|---|---|
| Part | Type | Size | Found | Datasheet |
| 2616 | Factory Mask Programmed ROM |
8 x 2048 (2k) | Installed in R7, U7 Space Wars Space War |
|
| 9316 | Factory Mask Programmed ROM |
8 x 2048 (2k) | Installed in R7, U7 Starhawk Space War |
|
| 82S2708 | User Programmable PROM |
8 x 1024 (1k) | Installed in P7, R7, T7, U7 Starhawk? |
|
| 82S181 | User Programmable PROM |
8 x 1024 (1k) | Installed in P7, R7, T7, U7 Space War |
Phillips |
| 8332 | Factory Mask Programmed ROM |
8 x 4096 (4k) | Installed in P7, T7 Tailgunner |
|
| Identifying Factory Mask Programmed ROMS | ||||
|---|---|---|---|---|
| Location | Cinematronics Vectorbeam ID |
Capacity | Game | Photo |
| U7 | 2147 | 8 x 2048 (2k) | Space Wars Space War |
- |
| T7 | - | - | - | - |
| R7 | 2148 | 8 x 2048 (2k) | Space Wars Space War |
- |
| P7 | - | - | - | - |
| U7 | 3-50002 | 8 x 2048 (2k) | Starhawk | - |
| T7 | - | - | - | - |
| R7 | 3-50001 | 8 x 2048 (2k) | Starhawk | - |
| P7 | - | - | - | - |
| U7 | 2151 | 8 x 1024 (1k) | Starhawk? | - |
| T7 | 2152A | 8 x 1024 (1k) | Starhawk? | - |
| R7 | 2153 | 8 x 1024 (1k) | Starhawk? | - |
| P7 | 2154 | 8 x 1024 (1k) | Starhawk? | - |