cocoacrumbs
Stewart RussellTom Pittman's “A Short Course in Programming” for the RCA 1802 as PDF and EPUB
#RetroComputing #CDP1802 #Cosmac #RCA #1802
https://scruss.com/blog/2025/10/18/tom-pittmans-a-short-course-in-programming-for-the-rca-1802/
Blinky running on the 1802. Best proof I have a genuine one.
Probably because the age counter keeps ticking up relentlessly I became nostalgic to build a retro computer based around the very first CPU that introduced me to (and started my career in) computers, the CDP1802 (which is still in production at Renesas!). That must be about 45 years ago...
Just sent the first PCB designs to JLCPCB. With some luck the adventure can start again somewhere next week.
Also, wouldn't know how to achieve this without #kicad
Mark J. BlairGood news: Got my RCA VP3301 video terminal with #CDP1802 CPU and RCA VIS chipset this weekend!
Bad news: DIN plug I ordered from Digi-Key for power input was missing one of the pieces needed to assemble it.
Good news: Raised the issue on the Digi-Key web site, and notice of replacement part shipment being approved arrived very quickly, even though it's late Sunday evening!
Bad news: I have not powered up the terminal yet.
Good news: I did dump the terminal's ROM, which is not believed to be archived yet by the #COSMAC community! It was even my first time actually using my #glasgowinterfaceexplorer for a real purpose.
Bad news: While the terminal came with a user's manual and a schematic of the UART subsystem, it didn't include a full schematic, so it'll take some work to figure out the address map and whatnot.
Good news: Reverse engineering old computers is fun!
radventureI keep throwing "COMX-35" in to a search bar at least fortnightly, hoping to stumble across new homebrew hardware or games, news etc..... searches usually don't show anything new but I did dig a bit deeper on a vague link, which ended up being a nice article at chiptune.cafe, discussing the CDP1869 CDP1870 / VIS
"The CDP1869 has two channels available: one, a square wave tone with an impressive range of 8 octaves, and the other a white noise generator that has 8 accessible pitches. With these, they had volume control over 16 steps."
The COMX-35 VIS/CDP1869: A Strange Chip for An Old Machine - The Chiptune Café
During the Microcomputer Craze of the late 70’s and early 80’s, the computer market saw a massive upsurge in the amount of new computers hitting the scene. Many famous sound chips widely used in the chip scene first debuted in computers that were released during this era, with probably the most well known example being the SID Chip in the Commodore 64. However, not all sound chips from this era were as popular as the aforementioned SID. Many of these ancient sound chips have faded into relative obscurity, rarely ever seen mentioned on the modern chip scene. The COMX-35, styled as the “Clever… …
🇺🇦 haxadecimal 🚫👑My CDP1802-equivalent RTL core can run at 166 Mhz in an XCKU5P Kintex Ultrascale+ FPGA (-1 speed grade). Given that my core takes exactly 1/8 as many clocks per instruction as a real CDP1802, this means that it will run at the equivalent speed of a 1.33 GHz CDP1802.
The real CDP1802 typically ran at 2.0 to 3.2 MHz.
#fpga #cdp1802 #cosmac
The real CDP1802 typically ran at 2.0 to 3.2 MHz.
#fpga #cdp1802 #cosmac