Recent content by RedskullDC

Further reading : https://www.ece.uvic.ca/~fayez/courses/ceng465/lab_465/project1/adders.pdf

Hans, What kind of Expansion Interface do you have? The earlier, buffered cable units have 5V on Pin #39, don't plug one of those in! The later, re-designed EI boards have pin 39 as NC (Not Connected), so you should be ok with one of those. Regards, Leslie

Hi Hans, The trace cut and join may not be related to the reset switch being removed. The trace cut/bridge mod removes +5V from pin 39, and changes it to GND. (Like the Japanese Model 1). Will stop it running with small expansions which draw 5V from the motherboard. A Momentary switch...

Hi Wells, The ROMS are HN61364P , which have selectable polarity on the chip select from the factory. IC5 is probably OK, but you may need to insert an inverter gate (74LS14 etc.) on the chip select signal to get the data out of it? I have a standard Japanese Model 1, also manufactured by...

Try https://www.facebook.com/groups/4609469943/ Plenty of VTECH experts there. Regards, Leslie

Hi, Link to V8.92 (2021-05-04) of the Top Software: https://mega.nz/file/g1clRQSC#cGLaB8evvP9RyaYj67L6jmOnfnp977ijVOSWSx_cpLU Works fine on XP for me: Regards, Leslie

Hi twolazy, Thanks for the reply, but that manual doesn't have what I need. Since my first post, I've procured another FP BASIC cartridge (below). More pics here: https://github.com/RedskullDC/Laser_3000_DSE_Cat/tree/main/Pics/FP_BASIC_cart2 Suspect it will be a reverse engineer job...

Hi All, Probably a long shot, but I'm hoping someone may have a copy of the small manual which came with the Laser 3000 FP BASIC cartridge? Specifically, I'm looking for a copy of the schematic which VTECH often included with their equipment. For example, here is the schematic that came...

Cheers from Oz! Quite an active Facebook group for the VZ/Laser series at: https://www.facebook.com/groups/4609469943/ (In case you weren't aware). Regards, Leslie

Hi Al, et al. Works fine for me under Windoze or Linux using a virtual machine. Cheers, Leslie

Clock cycle counts will only be valid when running at 1MHz. At high speed, the MEGA II chip inserts refresh cycles for the DRAM's, effectively slowing the CPU by about 8%. See page #24 , "RAM CONTROL" of the Hardware ref manual: http://www.applelogic.org/files/GSHARDWAREREF.pdf Cheers, Red

Got interested in Electronics/Ham Radio after one of our Geography teachers let on that he was an old time HAM, and would be happy to devote some of his lunchtimes to helping those interested to become proficient in Morse/Radio Theory. (It helped as I became VK2VCY and later VK2LR here in AU)...

That is a board designed for the OSI 48 Pin bus. (Ohio Scientific) Not sure why it has dual rows, possibly to accommodate different types of header connectors? Here is an OSI 470 disk controller for comparison. You can see the beefy power traces (highlighted) match those on your board...

Hi Daz99, You certainly can power it without using the stock power supply. I have a 300W AT power supply I use to power mine. It has 6 different power leads coming out of it to power a few other old systems (BBC, Apple2c, MicroBee etc.). Assume you have a USA model 1, not Japanese? (Let me...

Hi Falter, Robbbert, et al. Try this and let us know what you get: #SHOW ALL CHARACTERS 10 FOR T = 0 TO 255 20 POKE 57344+T,T 30 NEXT 40 FOR T = 0 TO 255 50 poke 53248+T,T 60 NEXT RUN # TURN COLOUR ON POKE 56832,4 Should look something like: Cheers, Red