I’m restoring an Astrocade and would like to build a Balcheck.
Good luck with that project. We gotta save all of the Astrocades that we can, right?
I’ve reviewed the plans and photos on Bally Alley (awesome websi
I'm glad you like the website. There's plenty of information there, if you're willing to dig around (as you've discovered).
te!). I’d like to create a PCB with parts that are currently in production. Can anyone recommend a modern alternative to the 2716 EPROM used on the Balcheck device? I’d prefer an EEPROM or Flash with very similar functionality. A quick search on Mouser returned the Microchip AT28C64B. It’s larger than need but I can ground the unused addresses A11 and A12. Also I have a TL866 so I can easily program it.
I don't have experience with the AT28C64B, but I just recently tried out, for the first time, the 128KB SST39SF010A with the AstroCart (a not-readily-available EEPROM cart for the Astrocade) and it works good. You might also try the 256K or 512K EEPROM s in the same series. They're all readily available and still in production.
If you're trying to trouble-shoot your Astrocade, then you may find these documents helpful too:
1) Troubleshooting the Power Supply in the Bally/Astrocade Home Computer System, by Michael Matte (MCM Design) - This article is for the individual desiring to learn how to troubleshoot the power supply in the Bally/Astrocade home computer. Included is info and troubleshooting tips that may help locate a failure within the power supply. I hope that this information proves helpful to those with failing Astrocades. Remember, working with power supplies can be dangerous; be careful!
2) Astrocade Videocade Cartridge PC Board Modification for 28 Pin Chip Example - How to Modify an Astrocade Cartridge PC Board for a 28-Pin Chip. By Michael Matte. 2017. - Videocade PC Board Modification for 28 Pin Chip: Example. Attached schematic shows an example of utilizing a 28-pin EPROM/EEPROM in a standard videocade cartridge. Drawing shows traces cut with a sharp utility knife and rewired. Basic instructions are also included.
3) Troubleshooting the Bally/Astrocade Motherboard Power-Up with SetScreen, A New Tool. - By Michael Matte - This document is for anyone with experience in troubleshooting the Bally/Astrocade motherboard. It explains one method on how to fix an Astrocade using step-by-step methods. It was written by Michael Matte, the person who designed and built a modified Astrocade that runs with low or high resolution graphics. Specifically, this document addresses the scenario in which a blank TV screen appears when powering on a motherboard and describes a new, very useful tool to help isolate the problem area. Note that Setscreen has been updated. The new version of the software sourcecode is available in the document SetScreen 2 - An Upgraded Bally Arcade/Astrocade Troubleshooting Utility available in number 4, below.
4) SetScreen 2 - An Upgraded Bally Arcade/Astrocade Troubleshooting Utility by Michael Matte. - SetScreen 2 is an improved version of the original SetScreen, a machine language routine. Setscreen 2 is a visual troubleshooting tool that can be used to help diagnose a failed Astrocade motherboard producing a blank TV screen at power-up. Details are provided in Troubleshooting the Bally/Astrocade Motherboard Power-Up with SetScreen, A New Tool. SetScreen 2 now has added routines to help a troubleshooter further investigate what is or is not going on with a motherboard graphics-wise and to provide more information to diagnose and isolate a problem area. A read routine is also included for a user who can connect a homemade dual 7-segment display.
As an aside, Michael Matte is currently working on a hi-res version of the Bal-Check software. Of course, you need to have a high-resolution Astrocade in order to use it... so that eliminates everyone except for his personal unit.
I figure all the other IC’s can be replaced by a single inexpensive MCU. I’ll post the Eagle files when I’m done.
I've always wanted to try getting some PCBs created with Eagle files. Perhaps this is my chance? Then again, my experince with MPUs is limited. I'm interested to see what you come up with when you're done.