Support for Vectrex models with latest BIOS (7ADB)

hcmffm · October 31, 2016, 05:08:27 PM

Currently, the Vectrex32 (Version 1.0) doesn't run at all on the Vectrex models with the latest BIOS (BIOS checksum 7ADB, Serial #31xxxxxx and 4xxxxxxx). This should be fixed because people who order a Vectrex32 SmartCart might end up with nothing at the moment.

Vectrex32 · October 31, 2016, 05:21:53 PM

I thought the issue was that the cartridge port did not have the -CART signal. Do you have reason to believe it's a BIOS issue? Any idea what the difference between the BIOSes is?

- Bob

hcmffm · October 31, 2016, 05:51:03 PM

Quote from: Vectrex32 on October 31, 2016, 05:21:53 PMI thought the issue was that the cartridge port did not have the -CART signal. Do you have reason to believe it's a BIOS issue? Any idea what the difference between the BIOSes is?

I'm not deep in technical Vectrex stuff and had thought that the different BIOSes cause the problem. So a missing -CART signal (whatever this means) is the problem. Is there are possible work-around or fix for this in sight?

(I think for selling the Vectrex32 to the "masses" it would be quite important that the Vectrex32 runs on all Vectrexes, regardless which BIOS or Vectrex model version.)

Vectrex32 · October 31, 2016, 06:02:23 PM

The missing -CART signal requires a hardware change to the Vectrex32.

- Bob

hcmffm · October 31, 2016, 06:10:34 PM

Quote from: Vectrex32 on October 31, 2016, 06:02:23 PM
The missing -CART signal requires a hardware change to the Vectrex32.

O.k., I was afraid, so. It's good that you have a hint in your ebay sales auction for the Vectrex32 till the hardware change happens.

crcasey · November 14, 2016, 04:31:03 AM

Quote from: Vectrex32 on October 31, 2016, 06:02:23 PM
The missing -CART signal requires a hardware change to the Vectrex32.

- Bob

So this then begs the question, what is your hardware using the _Cart line to do? How do other hardware multi-carts and things like Richard's vecRam manage without crashing out on the revised logic boards?

Thanks
-Cecil

hcmffm · November 14, 2016, 05:01:44 AM

Quote from: crcasey on November 14, 2016, 04:31:03 AM...How do other hardware multi-carts and things like Richard's vecRam manage without crashing out on the revised logic boards?

The missing _CART signal can be gained with some additional hardware, see topic Multicart on no-buzz models in the Vector Gaming forum.

crcasey · November 14, 2016, 12:13:15 PM

Quote from: hcmffm on November 14, 2016, 05:01:44 AM
Quote from: crcasey on November 14, 2016, 04:31:03 AM...How do other hardware multi-carts and things like Richard's vecRam manage without crashing out on the revised logic boards?
The missing _CART signal can be gained with some additional hardware, see topic Multicart on no-buzz models in the Vector Gaming forum.

Well that looks like a rather simple fix.

Diodes added on to pins 12 and 16 and add a pull up resistor to v+. Then instead of pulling *CART signal from the edge connector on pin 34 you would have full function on all models.

This could be bodged onto the existing PCB, but would be an obvious upgrade on the next order of boards.

-C