Interesting off_site dissections:
GitHub
emu-russia: dissection of NMOS 65xx CPU core and NES chips //Nintendo Entertainment System
pastraiser.com:
65CE02 dissectionzimmers.net:
C64 PLA dissected by Thomas ’skoe’ Giesel
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List of chip dissections in our forum:
[Dec 2023]
Rockwell R6545R1 CRT controller
[Jul 2023]
MOS 8364R7 Amiga Paula //4 channel PCM audio + interrupt controller + analog joysticks + UART + floppy controller
[Mar 2023]
CSG 8551R2 HMOS-II implementation of the 6551 UART
[Dec 2022]
MOS 5719 Amiga GARY //small CMOS gate array //
some CMOS basics explained.
[Dec 2022]
MOS 6520 PIA, cousin of MC6820\MC6821 //and of W65C21 somehow.
[Nov 2022]
MOS 8521 C64\C128 CIA //BCD TOD, HMOS-II implementation of the 6526
[Oct 2022]
MOS 8520 Amiga\1581 CIA //binary TOD
[Jul 2022]
MOS 6522 VIA
[Apr 2022]
Nintendo Entertainment System PPU\APU Your princess is in another castle.
[Jan 2022]
MOS 6525 CBM-II\1551 TPI //6523 is a 6525 subset, 6529 is a 6523 subset.
[Dec 2021]
MOS 6509 CBM-II CPU + MMU //full dissection of the NMOS 65xx CPU core.
[Oct 2021]
MOS 8726 C64\C128 REU //RAM extention unit
[Jul 2021]
MOS 6530 KIM-1 RRIOT //6532 is a 6530 variation.
[Jul 2021]
MOS 6702 SuperPET dongle chip
[May 2021]
MOS 8501 C16\+4 CPU //C64 8500\6510 is a 8501 subset.
[Sep 2018]
MOS 8701 C64 clock generator chip
[Jun 2016]
MOS SID C64\C128 famous/infamous sound chip
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The stone quarry:
(planned) STMicroelectronics EF9367
PET, NKC Graphic Display Processor
(planned) MOS 8373R4
Amiga ECS-DENISE
(planned) U880 Bugfixed Z80; GDR clone
(microscopic pictures) MOS 6572R1
C64 VIC-II PAL-N latest revision
(microscopic pictures) MOS 6567R9
C64 VIC-II NTSC latest revision
(microscopic pictures) MOS 6569R5
C64 VIC-II PAL
(microscopic pictures) MOS 6526R4
C64\C128 "Old" CIA; NMOS
(microscopic pictures) MOS 6560
VIC-20 VIC-I NTSC
(microscopic pictures) MOS 8360R2 and MOS8360R3
C16\+4 TED
(microscopic pictures) MOS 8365
C16\+4 TED PAL-N
(microscopic pictures) MOS 252535-01
C64C Memory Controller
(microscopic pictures) CSG 8375
Amiga ECS-AGNUS
(microscopic pictures) MOS 8362
Amiga DENISE
(microscopic pictures) MOS 5721
Amiga Bus arbiter
(microscopic pictures) Z80A (Z8400APS)
(vectorization in progress) CSG 6581R4AR
C64\C128 SID
(vectorization in progress) WD1772PH02-02 floppy controller
(vectorization in progress) MOS 6561
VIC-20 VIC-I PAL
(vectorized) MOS 8580R5
C64\C128 HMOS-II implementation of the SID
(vectorized) SSI263AP / Votrax SC-02 speech synthesis chip
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(dissection in progress) MOS 6571R7
Amiga Keyboard controller. //Microcontroller with 6502 core.
Attachment:
6571r6_orientation.png [ 539.68 KiB | Viewed 611 times ]
I can confirm that there are four 8 Bit I\O ports and a 16 Bit timer, but I found no shift register.
Address decoder PLA (6b) is sending some of the select signals through the data bus during PHI1.
RAM (7c) and ROM (8c) use a common row address decoder (9b),
and the designers had used an ingenous/devious trick to build that decoder with fewer transistors than one might expect.
To me, the 6502 core looks like a redesign, I'm now trying to capture the mill.
You won't expect a keyboard controller to support decimal mode, but it does.
The status register is crammed into the mill, between PC counters and the data bus driver.
//The designers _literally_ had folded the 6502 PLA to make it fit into the chip space.
Mill of the 6502 core inside the 6571:
Attachment:
6571_mill.png [ 239.97 KiB | Viewed 341 times ]
Control circuitry betwen the mill and the PLA is a lot of random logic.
Layout looks completely different from the NMOS 6502.
Attachment:
6571_core_control.png [ 692.31 KiB | Viewed 41 times ]