Recreating Atari XL / XE floppy disks

  • Posted on: 21 November 2016

There is plenty of free software available for the 8-bit Atari XL / XE computers online in the form of ATR files. These are image files created from the physical disks. A hudge database can be found on Atari Mania website. It is possible to mount these images with an Atari XL /XE emulator like Atari800Win. AtariAge website has an extended description on how to do it. However in this blog I am going to describe how to create floppy disks from these downloaded images so they can run on a real Atari XL / XE computer with a floppy disk drive.

C64 Basic ROM in 27C64 EPROM

  • Posted on: 19 November 2016

A while back I have bought a cheap second hand Commodore 64. Unfortunately it was broken, next to the PLA chip which I have fixed by buinding a custom CPLD version of it, the BASIC ROM chip (901226-01) was also broken. At the moment it is only possible to buy one that is salveged and the ones that I found were around 8 euros. A cheap alternative is to burn your own EPROM version of it.


Commodore 64 PLA chip replacement

  • Posted on: 17 November 2016

The most important chip in commodore 64 computer is the PLA chip. When this chip is broken, nothing will work and most certainly you will get a black screen after you try to turn it on. The original replacement chip is hard to get and if you find one it is not cheap. Luckily there are alternatives for replacement. It is possible to create one using EPROM, however the results of it's performance vary, or you can buy one on the market like SuperPLA, realPLA, U17 PLAnkton or PLAtinum.

Blinking LED with Altera EPM3064 CPLD

  • Posted on: 13 November 2016

FPGA's and CPLD's are certainly very cool devices. It is possible to create you own logical circuits and emulate real hardware chips on the lowest level. For this test project we will use Alera CPLD which is also known as MAX3000A and it's full code is ALTERA  EPM3064ATC44-10. It has a programming capacity of 64 macrocells. A macrocell is the smallest programmable part inside a CPLD. The capacity of 64 is not very large compared for example to Altera Cyclone IV EP4CE6E22C8N FPGA chip which has 6272 logical elements, but it will be suitable for small projects.