Sothius' Home of Ancient Microcomputers - Commodore 64C (ASSY 250469)

Commodore 64C

C64C logo (6 KBytes)

Commodore 64C

Commodore 64C ASSY 250469 (54 KBytes)

The C64C is, in my opinion, the most beautiful of them all (except for the golden one, of course). Behind it, hower, two CBM diskdrives: CBM 1541C (right, in C64C-style) and the rarer CBM 1570
(picture copyright by M.A.Grundke)

Specifications

Name Commodore 64C
sometimes referred to as 'C64-II' - see misc

Made by Commodore Business Machines (CBM)

Released
May 1986 (first version C64C)
this ASSY 250469 machine was made in 1989, indicated by the chips' production dates

Serial-No. HB4 1428155E

Board-info
PCB ASSY NO. 250469
PCB NO. 252311 REV.A
this board revision ASSY 250469 ('C64 version BN/E') came up with the C64G. Since the C64C was still sold these days, latest machines (like this one) are also 'BN/E'. It's cost-reduced in many ways, see board overview

CPU CSG 8500 (6510 code-compatible, HMOS-2 process)
The 'CSG' means Commodore Semiconductor Group and was the new name of MOS Technologies, which was renamed these days
there were also (early) machines with MOS 6510 (NMOS)

Speed 985.248 KHz (PAL)/ 1.0227 MHz (NTSC)

RAM SHARP LH5062B MMU (MOS partno. 251715-01)
64 KBytes:
2 pcs. SHARP LH2464-12 (64Kx4)
additional SANYO LC3514A-15 (1Kx4 SRAM) for storing screen color data ('color RAM')
up to 16 KBytes can be addressed as video-RAM by VIC-II
expandable to 576 KB/ bankswitched (CBM 1750 RAM-expansion)

ROM/ Native OS C251913-01 Commodore BASIC V2 + CBM C64 KERNAL Rev. 3
C901225-01 character-generator ROM
in overall 20 KBytes ROM
In this final C64 board-layout, BASIC and KERNAL-ROM have been merged into one

Keyboard/ Layout 66 keys/ US (QWERTY) layout
latest C64G and C64C (like this particular machine) came with a different keyboard, where the special characters are on top of the keycaps (instead of being printed onto their front)

Graphics CSG 8565R2 'VIC-II' ('Video Interface Controller')
MOS 8701 clock generator
Max.Resolution: 320x200 pixels ('high-res')
40x25 attribute cells, each 8x8 pixel in size
2 colors per cell (background, foreground)
Max.Colors: 16 ('multi-color' @ 160x200 pixels)
40x25 attribute cells, each 4x8 pixel in size
4 colors per cell (3 foreground + background)
most common mode for games

with tricks (such as combining two multi-color modes with interlace, or forcing BAD SCAN LINE at each raster line), it is possible to use up to 16 colors per attribute cell, or to increase the palette to 128 colors. However, since these modes all have major drawbacks (such as interlace flicker, extensive CPU- and VIC-cycle usage), they're mostly used for demos
furthermore, VIC-II can create up to 256 movable display objects ('sprites'), 8 per line, and max. 21x24 pixels each
Text: 40x25 characters with graphical charset
this is a PAL-B version; the NTSC-M version of 'VIC-II HMOS-2' is called CSG/MOS 8562

Sound CSG 8580R5 'SID' ('Sound Interface Device')
3 independant voices, each with 9 octave range (0.1Hz-4KHz in 0.059Hz steps)
4 waveforms (sawtooth, triangle, variable pulse & noise)
programmable ADSR (attack, delay, sustain, release) envelope generator
programmable filter, independantly selectable for each voice (low pass, high pass, Band pass, notch outputs)
master volume control

Media
standard Audio-cassettes (via CBM VC-1530 'Datasette')
5.25" disks, 170 KBytes/ disk (all CBM serial drives like CBM 1541, CBM 1541C, CBM 1541-II, CBM 1570 and so on)

other CBM-drives via IEE488-interface
3.5" disks (CBM 1581), 800 KBytes/disk
harddisks up to 30 MBytes

Input/ Output 2x CSG 6526A 'CIA' ('Complex Interface Adaptor')
PLA-functions integrated in MMU
2x 9 pin joystick/ mouse/ paddles/ lightpen
44 pin female edge conn. cartridge interface
8 pin DIN-41524 audio/video
6 pin round-DIN CBM serial IEC-bus (printer or up to 5 diskdrives)
12 pin male edge conn. CBM cassetteport
24 pin male edge connector 'user-port' (8 bit programmable I/O, e.g. used for modems, centronics-adaptors)
RF TV-out
7 pin round-DIN power supply-conn. (9V)

Miscellaneous
In my opinion the C64C, with its 'C128-like design', is the most beautiful C64 ever. But many disliked it because its case hadn't got enough room for internal expansion (floppy-speeders, alternative ROMs etc.). Additionally, its case was of a higher quality (better shielding, metal stands supporting the keyboard), making production more expensive
Especially in Germany this machine was often called 'C64-II' - although most people consider the 1987-released C64G the official 'model II'

This is a machine with the 'BN/E' board; it's identical to the ones used in the C64G-series, from the time it appeared (producing C64C and G with the same board reduced the cost, of course). However, there were also C64Cs using older '65xx-boards' (ASSY 250441/250466, maybe?)
This machine's chips indicate, by the way, that MOS Technologies had already become Commodore Semiconductor Group by that time
Together with the C64C, Commodore and Berkeley Softworks introduced GEOS, a graphical user-interface (GUI) with mouse support and unique in the world of 8 bit machines (see below). Even nicer, however, was GEOS128 for the 128-series, since it added 80-column support

'GEOS 2.0' screenshot 1 (24 KBytes) 'GEOS 2.0' screenshot 2 (24 KBytes)

GEOS 2.0 screenshots: On the left the copyright notice, on the right GEOS' preferences menu. Interesting is that Berkeley Softworks also released GEOS128, which made use of the 128-series' improved capabilities (such as higher resolution and 80-column mode)

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Sothius' Home - Museum - Commodore - Commodore 64C - additional pictures

Name	Commodore 64C sometimes referred to as 'C64-II' - see misc
Made by	Commodore Business Machines (CBM)
Released	May 1986 (first version C64C) this ASSY 250469 machine was made in 1989, indicated by the chips' production dates
Serial-No.	HB4 1428155E
Board-info	PCB ASSY NO. 250469 PCB NO. 252311 REV.A this board revision ASSY 250469 ('C64 version BN/E') came up with the C64G. Since the C64C was still sold these days, latest machines (like this one) are also 'BN/E'. It's cost-reduced in many ways, see board overview
CPU	CSG 8500 (6510 code-compatible, HMOS-2 process) The 'CSG' means Commodore Semiconductor Group and was the new name of MOS Technologies, which was renamed these days there were also (early) machines with MOS 6510 (NMOS)
Speed	985.248 KHz (PAL)/ 1.0227 MHz (NTSC)
RAM	SHARP LH5062B MMU (MOS partno. 251715-01) 64 KBytes: 2 pcs. SHARP LH2464-12 (64Kx4) additional SANYO LC3514A-15 (1Kx4 SRAM) for storing screen color data ('color RAM') up to 16 KBytes can be addressed as video-RAM by VIC-II expandable to 576 KB/ bankswitched (CBM 1750 RAM-expansion)
ROM/ Native OS	C251913-01 Commodore BASIC V2 + CBM C64 KERNAL Rev. 3 C901225-01 character-generator ROM in overall 20 KBytes ROM In this final C64 board-layout, BASIC and KERNAL-ROM have been merged into one
Keyboard/ Layout	66 keys/ US (QWERTY) layout latest C64G and C64C (like this particular machine) came with a different keyboard, where the special characters are on top of the keycaps (instead of being printed onto their front)
Graphics	CSG 8565R2 'VIC-II' ('Video Interface Controller') MOS 8701 clock generator Max.Resolution: 320x200 pixels ('high-res') 40x25 attribute cells, each 8x8 pixel in size 2 colors per cell (background, foreground) Max.Colors: 16 ('multi-color' @ 160x200 pixels) 40x25 attribute cells, each 4x8 pixel in size 4 colors per cell (3 foreground + background) most common mode for games with tricks (such as combining two multi-color modes with interlace, or forcing BAD SCAN LINE at each raster line), it is possible to use up to 16 colors per attribute cell, or to increase the palette to 128 colors. However, since these modes all have major drawbacks (such as interlace flicker, extensive CPU- and VIC-cycle usage), they're mostly used for demos furthermore, VIC-II can create up to 256 movable display objects ('sprites'), 8 per line, and max. 21x24 pixels each Text: 40x25 characters with graphical charset this is a PAL-B version; the NTSC-M version of 'VIC-II HMOS-2' is called CSG/MOS 8562
Sound	CSG 8580R5 'SID' ('Sound Interface Device') 3 independant voices, each with 9 octave range (0.1Hz-4KHz in 0.059Hz steps) 4 waveforms (sawtooth, triangle, variable pulse & noise) programmable ADSR (attack, delay, sustain, release) envelope generator programmable filter, independantly selectable for each voice (low pass, high pass, Band pass, notch outputs) master volume control
Media	standard Audio-cassettes (via CBM VC-1530 'Datasette') 5.25" disks, 170 KBytes/ disk (all CBM serial drives like CBM 1541, CBM 1541C, CBM 1541-II, CBM 1570 and so on) other CBM-drives via IEE488-interface 3.5" disks (CBM 1581), 800 KBytes/disk harddisks up to 30 MBytes
Input/ Output	2x CSG 6526A 'CIA' ('Complex Interface Adaptor') PLA-functions integrated in MMU 2x 9 pin joystick/ mouse/ paddles/ lightpen 44 pin female edge conn. cartridge interface 8 pin DIN-41524 audio/video 6 pin round-DIN CBM serial IEC-bus (printer or up to 5 diskdrives) 12 pin male edge conn. CBM cassetteport 24 pin male edge connector 'user-port' (8 bit programmable I/O, e.g. used for modems, centronics-adaptors) RF TV-out 7 pin round-DIN power supply-conn. (9V)
Miscellaneous	In my opinion the C64C, with its 'C128-like design', is the most beautiful C64 ever. But many disliked it because its case hadn't got enough room for internal expansion (floppy-speeders, alternative ROMs etc.). Additionally, its case was of a higher quality (better shielding, metal stands supporting the keyboard), making production more expensive Especially in Germany this machine was often called 'C64-II' - although most people consider the 1987-released C64G the official 'model II' This is a machine with the 'BN/E' board; it's identical to the ones used in the C64G-series, from the time it appeared (producing C64C and G with the same board reduced the cost, of course). However, there were also C64Cs using older '65xx-boards' (ASSY 250441/250466, maybe?) This machine's chips indicate, by the way, that MOS Technologies had already become Commodore Semiconductor Group by that time Together with the C64C, Commodore and Berkeley Softworks introduced GEOS, a graphical user-interface (GUI) with mouse support and unique in the world of 8 bit machines (see below). Even nicer, however, was GEOS128 for the 128-series, since it added 80-column support


GEOS 2.0 screenshots: On the left the copyright notice, on the right GEOS' preferences menu. Interesting is that Berkeley Softworks also released GEOS128, which made use of the 128-series' improved capabilities (such as higher resolution and 80-column mode)