Questions tagged [chip]
General questions about computer chips and chipsets in retro hardware. Use a specific chip’s tag instead if available.
98 questions
1 vote
1 answer
164 views
ROM chip width to match 18-bit CPU [closed]
Early microprocessors typically had data bus width of 8 bits. Dynamic RAM chips were typically 1 bit wide, used in rows of 8, but mask ROM chips were typically 8 bits wide. As I understand it, this ...
- 65.3k
11 votes
4 answers
2k views
Embedding 2k of RAM into video chip in 1987
Was embedding 2048 bytes of RAM directly into video generating chip technically/economically possible in 1987? The RAM access scheme is to write individual bits and read 16-bit words randomly.
- 827
3 votes
2 answers
276 views
How to interface with W65C51 UART
I want to build my own computer with retro-ic's. One of those ic's that I want to use is the W65C51 from Western Design Center. I am trying to connect it to a Arduino to learn how to interface with ...
- 113
19 votes
2 answers
5k views
Did the NES CPU save die area by omitting BCD?
The NES CPU was a copy of the 6502 with the BCD circuitry removed. As I understand it, this modification was motivated by a theory that BCD was the only part of the 6502 that was actually patented, so ...
- 65.3k
3 votes
0 answers
271 views
What process node enabled the 6502 to reach 2 MHz? [duplicate]
The original version of the 6502 was rated for 1 MHz, but before the end of the decade, the CPU was available in a 2 MHz version. Presumably what changed was Dennard scaling: make the transistors ...
- 65.3k
1 vote
0 answers
253 views
VIC 6560, which parts do what?
I'm interested in the design of the VIC, the video and sound chip in the Vic-20. (Not too be confused with the VIC-II, which has been discussed elsewhere on the site.) I haven't been able to find an ...
- 65.3k
2 votes
0 answers
138 views
Where to find datasheets for MOS (Commodore) 85xx chips?
It seems difficult to find any detailed technical information online for the 85xx chips used in later Commodore 8-bit computers. For example, there's an excellent archive at http://www.6502.org/...
- 62.1k
3 votes
2 answers
383 views
Did anyone use quarter-bad RAM chips?
There was a time in the early 80s when 64k RAM chips had a significant defect rate, such that half-bad ones could be obtained at a discount. Some computer manufacturers such as Sinclair and Tandy took ...
- 65.3k