Protected: Riparazione telecomando Mivar
20 November 2021
Create a C64 cartridge from a PRG
7 December 2021
Finally I can find a Commodore 116 at a decent price, yes ok, no box, power supply and cables but will it work? ...
Guardate il video se non volete leggervi l’articolo 🙂 e iscrivetevi al canale !!
Aesthetically it is not in bad shape, just a clean of the plastics and it will be back again !. Here we see it compared with the plus / 4.
But cos'and the C116?
To be so cheap, they have reduced the number of chips and to manage everything we find the CPU (7501 or 8501) and the TED (8370), the latter manages audio and video .. a decent level of everything, even if it manages more colors , it has no support for sprites and this weighs on the graphics processor.
Let's move on to the test now
As soon as it was turned on, the basic screen appeared .. be that cu ... o !! well let's not say it too quickly, in fact the keys don't work and the computer seems to freeze even if the cursor is blinking. Switching off and on is always worse ...
Strange characters or even screen with nothing and finally black screen .. @ # !.
Beh, era troppo bello avere preso una macchina così delicati in ottime condizioni e pure funzionante 🙂
Now off to debug, but there is little to verify, 2 ram and 2 damn chips. Since I also have the C16 I immediately try the offending chips and here are the results
TED 1 CPU 0
What do you do now?
It is possible to replace the processor 7501 with the 6510 used in the C64 but it will be necessary to adapt the pins and above all to change the Kernal with new instructions to manage the hardware differences on this computer. This is not a beautiful solution because even with the ROM with added instructions the computer will not be fully functional, the old CPU also controlled the datassette engine which the 6510 does not do and had inside the op codes not officially declared but that the programmers they used to save code loops and they don't exist on the 64 cpu.
Here you will find the new replacements for the cpu:
https://lotharek.pl/productdetail.php?id=257
https://www.sellmyretro.com/offer/details/mos–7501~~8501-cpu-replacement-for-c16~~116~~%2B4-30475
