Denial

I estimate approximately 1.5s a full system ROM-RAM copy. Remember that at startup a reset HW is generated, and its length depends on 10uF electrolytic capacitor (1s? 5s?), then the kernal test the RAM banks and if RAM is expanded it take a lots of seconds.... If Commodore thinks the normal boot del...

The ROM-RAM copy take less than 1.5-2s, for example the prototype of "DREAMcard" load activity from startup to starting "Cheesy Trials": https://youtu.be/tAGjg8AVstk The VIC 20 used has a special kernal that is able to ignore the cart auto start, in this manner is evidenced the r...

what about a cart full of RAM that on startup will copy a .PRG file from a hidden ROM to the RAM? May be a new cheap standard to making cart from own .PRG software/games https://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?t=9950 https://sleepingelephant.com/ipw-web/bulletin/bb/download/fi...

Hi Joe,
I'm interested in getting information on the "not very functional modern PLA" and... how did you solve it?

Thanks

Have a look here:
http://sleepingelephant.com/ipw-web/bul ... php?t=9482

VIC20 does not have fully decoded addresses for chip selection, so some chips overlaps can be done. The overlaps become bus conflicts if a READ cycle is executed, but it can be used to WRITE the same value into the same register of both VIAs in the same CPU cycle, it can be useful for "raster r...

Yes,
SMART RAM is still available!

nefaurora: you have a private message....

A couple of years ago I developed the HW of a new multicart which uses a different approach to fill the EPROM and this means that many more files can be inserted (simultaneously even PAL/NTSC versions...). http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?t=9926 multicart.jpg The prototy...

Italian: BASIC (like BASIC language) - this is called BASIC, its a name ASSEMBLY - I'd not translate this either ("Assembler"). Also "Assembly" and "Machine Language" aren't the same thing :) "machine language"="linguaggio macchina" CONTROLLERS (like...

Why the old PAL & NTSC distinct Diagnostic tool version and not my pal/ntsc cable free hacked version of Diagnostic Tool? and why not my new DeadTest version with additional Keyboard and Video/Audio tests too? It's just a misunderstanding: "OLD" as "improved mbla000 CLASSIC"...

Now I'm thinking about a test set composed by the classic test-cables and a new diagnostic card. This new diagnostic board integrates 3 tools: 1) classic DEAD TEST program ( the version improved by nbla000 ) to test quickly without opening the VIC20 case 2) classic DIAGNOSTIC program ( the version i...

I tried to select the DC-DC converters CC CV but unfortunately all those I have seen on sale are not suitable because to measure the current they interrupt the ground line input-output with a small shunt resistor, while in our case the point of ground is unique in common between input and output. No...

The heat inside the old type of board can be drastically reduced by using a DC-DC converter in place of the 5V linear regulator (I suggest the DC-DC converter type with toroidal core). The heat inside is also generated by the diode rectifier bridge, but if the DC-DC converter is used the current on ...

nbla000 wrote: ↑Mon Mar 28, 2022 10:35 am Very Interesting info... but this hardware riquires someone is able to program a CPLD, unfortunately I'm not

Fortunately I can...

Another project into the "have to do" list...

Very interesting! C16 and PLUS4 have the Kernal rom always on socket so the "DIAG264" was created (an alternative ROM kernal that test the computer: diagnostic for '264 machines). Unfortunately in the VIC20 the rom of the kernal is very often soldered, so the "DIAG20" kernal rom ...