Inside the Vectrex
I recently read many interesting stuff on the Newsgroups about the buzz, the checksum numbers and the new parts that ebayzilla talked about (PIA 2Mhz instand of 1,6 Mhz) so I decided to get my 6 Vectrex systems and check them all to see weither there was someting interesting. Here is a sum up.
So, first, I inserted my Test cart in each system to get the checksum number. Then, I read the labels on the back and finally I opened each system to see what kind of components were inside. On the 6 systems, there were 3 different ones:
| Checksum # | Serial Number | On screen at start | Date on power board | main components | Comment |
| 7931 | 3 XXX XXX | Vectrex | 11th week /1983 | CPU: Hitachi 6809 PIA: SY6522 |
- |
| B796 | 3 XXX XXX | Vectrex Entertaining new ideas | 9th week / 1983 | CPU: Motorola 6809 PIA: SY6522 |
- |
| DA7B | 4 XXX XXX | Vectrex | 30th week / 1983 | CPU: Hitachi 6809 PIA: SY6522AP |
No buzz |
So, the result is quite simple: The last one with DA7B checksum is a modified "no buzz" system. The logic board is very different from the two other systems. Actually, the buzzer is wired directly to the Logic Board on the DA7B while it's linked to the Power Board on the 2 other systems. below are pix of the systems and close up of the "no buzz" system.
Also, the PIA 6522AP means that we have here a ehanced version with 2mhz instead of 1mhz for the SY6522 from what Ebayzilla says. In a recent auction, I learnt that most of the Vectrex had the 1mhz PIA and that only the last systems had the SY6522AP.
All the labels have the EURO Vectrex logo on them. Only the DA7B one has the US logo and Santa Monica references.
This is the normal wiring (from buzzer to power board) 7931 and B796 checksum
This is the "no buzz" system. DA7B checksum
On the "no buzz" system, the buzzer is directly linked to the logic board.
This is a close up on a B796 checksum system with a double (?!) socket and CPU...strange....
If you have anymore info on this and if you ever open your system and want to share your discoveries, do not hesitate to contact me. There are only 5 screws and it's very easy to open a vectrex...Concerning the checksum, if you don't have the test cart, you can use the test cart rom on the multicart. These were systems found in Europe, so, other countries systems might be different and it would be cool to know more. Thanx.
Contact: sap1@club-internet.fr