We just open-sourced DOS 4 (and found binaries of Multitasking DOS 4) https://www.hanselman.com/blog/open-sourcing-dos-4
We just open-sourced DOS 4 (and found binaries of Multitasking DOS 4) https://www.hanselman.com/blog/open-sourcing-dos-4 Did any companies build 40 pin DIP Z80s that were functionally identical to the original but had an 8 bit ALU so there were fewer clocks/instuction? here's a neat microcontroller. Dallas DS5000T. programs are stored in battery-backed RAM in an encrypted form.
Show previous comments
@tubetime The DS5002 was used for the suicide mcu in Gaelco arcade hardware. https://mamedev.emulab.it/haze/2017/07/17/ds5002fp-dumping/ @tubetime it looks almost exactly like Telecom Eireann's logo, backwards. https://www.flickr.com/photos/ajcarr/536570712/ (TE was the national telco of the Republic of Ireland) @tubetime I miss the days when computer peripherals had CPUs nearly as powerful as the main computer :D. one of today's pickups is this mystery Xebec RAM card. I can't find any information about it, so I think I'll try reverse engineering it. the chip pins are crimped. this is a huge pain even with the super nice desoldering tool (FR-301) @tubetime I love these posts. When I lived in the Bay Area I had no space for collecting fun old stuff, sadly and/or thankfully. I only made it to a couple of the flea markets just to look around.
Show previous comments
@tubetime Had to look that up. 512x8 EPROM. I think the smallest EPROM is worked on was 2k x 8. Also, that die attach is very sloppy looking by modern standards. today's mystery chip: the National Semiconductor MM5827D. I think it is a memory but I can't find any information about it. hmm could be a dual driver or comparator. it's got two beefy output stages. I don't see any compensation capacitors so I don't think it is an op amp. Do you know already or were you asking? It’s a 16-pin EEPROM, newer MB series are/were marketed as FRAM being faster and having greater flash cycles than traditional EEPROM but given that package it’s probably first gen FRAM or last gen EEPROM.
Show previous comments
@tubetime This is a custom chip used, for instance, in SONY VO-5850P. Below is an excerpt from the service documentation for VO-5850P: here's an utterly ancient RCA CMOS logic chip. this TA5677W is the development number that shipped as the CD4033. looks like a 1971 date code. @tubetime Have you found any cross-reference of TA to production numbers? I only know of about half a dozen.
Show previous comments
@tubetime telephony stuff? Edit: no, does not really match ss5. Decoding artifacts due to the internal gates? @tubetime I had to look up what that was, and... I guess I should have guessed, but still, weird packaging! you can read the maintenance manual for a passenger aircraft on the internet archive! (the Convair 880, probably the loudest subsonic aircraft ever)
Show previous comments
@tubetime Subsequent thought: it's part one of three, selected through the sidebar thingy. Blimey! (So many amazing illustrations...) here's an odd little beast: the Mostek 3870. a single chip implementation of the Fairchild F8 architecture. this one has a piggyback socket for the program ROM chip. Don't modern mobile SoC packages do the same thing but as BGA and for a RAM chip? Fairchild "borrowed" a microprocessor design from a typewriter company 🤷♂️ Some brief history here: https://www.eejournal.com/article/a-history-of-early-microcontrollers-part-6-the-fairchild-f8-and-mostek-mk3870/
Show previous comments
Show previous comments
@tubetime This is a weird one. Only pops up with a lot of aviation related hits, but NOTHING specific, let alone a spec sheet or something. Edit: Found something on a Russian parts site where it is listed under i/o relay modules. |
@shanselman Was MS-DOS 3.x ever released? When can we expect 5.x and 6.x?
Can we ever expect 7.x and 8.x? 😅
@shanselman cc @freedosproject
@shanselman Now we just need Windows XP… anything to help out #ReactOS become more stable!