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November 21, 2018Hardware Reference

Commodore Hardware Information

This post is divided into three sections. The first gives the CPU, memory, video and audio specifications for all models of C64 and c128. The second provides a list of common storage devices with information about their transfer speed, physical interface and software loader. The last section is a list of common storage devices along with their media type, capacity and additional usage notes.

Contents

Basic Information: C64 and c128

  C64
1
C64c
2
SX-64
3
c128
4
c128 D
5
c128 DCR
6
CPU Speed PAL:
985,248.4 Hz

NTSC:
1.022727 MHz
PAL:
985,248.4 Hz

NTSC:
1.022727 MHz
PAL:
985,248.4 Hz

NTSC:
1.022727 MHz
PAL:
985,248.4 Hz or
1.9704968 MHz

NTSC:
1.022727 MHz or
2.0454545 MHz
PAL:
985,248.4 Hz or
1.9704968 MHz
NTSC:
1.022727 MHz or
2.0454545 MHz
MIPS
(varies by instruction)
PAL:
0.1407143 to
0.4926242

NTSC:
0.1461039 to
0.5113635
PAL:
0.1407143 to
0.4926242

NTSC:
0.1461039 to
0.5113635
PAL:
0.1407143 to
0.4926242

NTSC:
0.1461039 to
0.5113635
PAL:
0.1407143 to
0.9852484

NTSC:
0.1461039 to
1.0227273
PAL:
0.1407143 to
0.9852484

NTSC:
0.1461039 to
1.0227273
PAL:
0.1407143 to
0.9852484

NTSC:
0.1461039 to
1.0227273
Base Memory 64 KB 64 KB 64 KB 128 KB 128 KB 128 KB
Maximum Internal Memory 256 KB ? ? 1 MB 15 1 MB 1 MB
Maximum Extended Memory 32 MB 32 MB 16 MB 7 32 MB 32 MB 32 MB
BASIC Free Memory 38,911 bytes 38,911 bytes 38,911 bytes 122,365 bytes 122,365 bytes 122,365 bytes
Display Device(s) VIC-II composite VIC-II composite VIC-II composite VIC-IIe composite and
VDC / RGBI
VIC-IIe composite and
VDC / RGBI
VIC-IIe composite and
VDC / RGBI
Resolutions
9
40x25 text
160x200 Multicolor mode
320x200 Hires color mode
40x25 text
160x200 Multicolor mode
320x200 Hires color mode
40x25 text
160x200 Multicolor mode
320x200 Hires color mode
VIC-IIe:
40x25 text
160x200 Multicolor mode
320x200 Hires color mode

VDC:
80x25 text
80x50 text
640x172 Hides color mode
640x200 monochrome mode
Interlacing available, but not useful
VIC-IIe:
40x25 text
160x200 Multicolor mode
320x200 Hires color mode

VDC:
80x25 text
80x50 text
640x172 Hides color mode
640x200 monochrome mode
Interlacing available, but not useful
VIC-IIe:
40x25 text
160x200 Multicolor mode
320x200 Hires color mode

VDC:
80x25 text
80x50 text
640x200 to 640x600 Hires color mode
640x200 to 720x750 Hires monochrome
Interlacing available where Y resolution exceeds about 300 lines.
Video RAM 1 K x 4 plus part of base memory
11
1 K x 4 plus part of base memory 1 K x 4 plus part of base memory VIC-IIe: 2 K x 4 plus part of base mem.
12
VDC: 16 KB 10
VIC-IIe: 2 K x 4 plus part of base mem.

VDC: 16 KB
VIC-IIe: 2 K x 4 plus part of base mem.

VDC: 64 KB
Color cell size 4x8 or 8x8 4x8 or 8x8 4x8 or 8x8 VIC-IIe:
4x8 or 8x8

VDC:
8x8 to 8x32
VIC-IIe:
4x8 or 8x8

VDC:
8x8 to 8x32
VIC-IIe:
4x8 or 8x8

VDC:
8x1 to 8x32
14
Colors 16 16 16 16 16 16
Hardware sprites Yes Yes Yes VIC-IIe: Yes
VDC: No
VIC-IIe: Yes
VDC: No
VIC-IIe: Yes
VDC: No
Sound Device 6581 8580 6581 6581 or 8580 8580 8580
Voices 13 3 3 3 3 3 3
Built-in Drive 1541 1571 1571
 

Storage Solutions, Approximate Speeds

Due to the c128's faster CPU and hardware burst mode, it may perform better than a C64. Quoted speeds are for a stock C64, unless otherwise noted. Speeds can vary depending on the software load routines, disk format, drive model, and the quality and kind of media.

The C64's stock KERNAL ROM includes datasette and IEC load routines that are notoriously slow. The IEC routines pass through standard vectors which can be wedged to access certain types of non-IEC-based devices. The KERNAL can be replaced by alternatives, such as JiffyDOS, fastloading routines can be added via plug-in cartridge to speed up software that uses the standard KERNAL routines, and software can also bypass the KERNAL altogether by writing their own faster routines.

Device Type Speed Interface Loader Notes
Datassette 45–60 bytes/sec Dedicated serial line KERNAL ROM Exact speed depends on binary program data.
Generic IEC
device
500–700 bytes/sec IEC Serial KERNAL ROM Exact speed varies slightly with drive model.
Datasette Up to 1 KB/sec Dedicated serial line Custom
(rturbo, etc)
 
1541 or 1571 6–7 KB/sec IEC Serial Fastloader  
1581 or FD2000 ~7 KB/sec IEC Serial Fastloader Exact speed depends on data layout.
CMD HD or CMD ZIP 7–8 KB/sec, maybe more IEC Serial JiffyDOS JiffyDOS is a replacement KERNAL ROM, and the most commonly used fastloader for CMD devices.
CMD HD or CMD ZIP 7–8 KB/sec, maybe more IEC Serial JiffyDOS JiffyDOS is a replacement KERNAL ROM, and the most commonly used fastloader for CMD devices.
SD2IEC ~8 KB/sec, maybe more IEC Serial JiffyDOS SD2IEC is also compatible with other common fastloader cartridges.
CMD HD or CMD ZIP 15–20 KB/sec RAMLink Parallel Bus Supplied by RAMLink The drive switches to parallel mode if it detects a connection to a RAMLink.
SFD-1001 ? IEEE/Parallel on Expansion Bus Supplied by IEEE Interface Speed should be comparable to a parallel 1541.
1541 or 1571 12–20 KB/sec User Port Parallel Fastloader Either a software–loadable fastloader or a replacement ROM chip. (i.e. Dolphin DOS)
CMD RAMLink ~30 KB/sec Expansion Bus JiffyDOS (supplied by the RAMLink)  
IBM compatible PC/interface cable ~35 KB/sec IEC Serial or User Port Parallel Fastloader A PC is used as the storage device.
IDE64 ~50 KB/sec Expansion Bus Supplied by IDE64  
CMD RAMLink 200–250 KB/sec Expansion Bus, via SuperCPU Accelerator Custom
(not JiffyDOS)
Speed estimated by Chester Kollschen

Drive Sizes and Capacities

Device Maximum storage Media Type Notes
Datasette Typ. 100+ KB per 30 minute side using stock load/save routines Standard audio casette tapes Exact storage depends on tape length and specific load/save routine used.
1541 170 KB to 190 KB 5.25" SSDD or DSDD floppies Normally stores 170KB unless you extend it to 40 tracks with a custom load/save routine
1571 340 KB to 380 KB 5.25" DSDD floppies Normally stores 340K on a double-sided formatted disk. Up to 380KB if you use all 80 tracks.
1581 800 KB 3.5" DSDD floppies  
SFD-1001 1 MB 5.25" DSDD 96TPI floppies  
CMD
FD-2000
1.6 MB 3.5" DSHD floppies Standard floppies as used for PC 1.44 MB format
CMD
FD-4000
3.2 MB 3.5" DSED floppies Standard floppies as used for PC 2.88 MB format
CMD RAMDrive 512 KB, 1MB or 2MB Solid State RAMdisk Size depends on specific model
CMD RAMLink 1 MB to 16 MB Solid State RAMdisk (30-pin SIMMs) Provides four 30-pin SIMM slots. Can also use an REU in the dedicated REU port.
CMD HD or
CMD ZIP
20 MB to 4 GB Standard SCSI I/II hard disks, ZIP drives, or CD-ROM drives Hard Disk is replaceable. Third–party software is required for CD-ROM access.
IDE64 Up to 128 GB (128,000 MB) 40-PIN IDE hard disks, CompactFlash cards, or CD/DVD-ROM drives Hard disk and CompactFlash card are user-replaceable.
SD2IEC Up to 128 GB SD Cards, microSD cards with an SD adapter SD Cards can be hotswapped.
1541 Ultimate II+ No practical limit Thumb drives, or USB-based hard disks and card readers USB storage devices can be hotswapped. Access to native file system requires software support for the Ultimate DOS api.
IBM compatible PC/interface cable No practical limit Uses a PC as a storage device. Maximum storage is limited only by the PC and its software capabilities.

Thanks and Credits

The source of most of the information on this page, and the inspiration to reproduce and update it here, comes from Vanessa Dannenberg's General Commodore Information page.

Information about SD2IEC comes from Mingo's CommodorePage.

  1. The original C64 is often called the "breadbin" or "breadbox." []
  2. Filtering circuitry improved with the 8580 SID. Uses a smaller mainboard, called the shortboard. Has a sleeker, sexier case than the original C64. []
  3. The cassette port was removed and the KERNAL ROM was updated to make the built–in 1541 drive, device 8, the default device. []
  4. The regular c128 is somtimes called the "flat 128." All modes on the VIC-IIe are identical to the C64 except that a few more tricks are possible using 2MHz fast mode. The VDC's modes are mildly extendable and mostly don't require active software tricks. []
  5. The c128 D, sold in Europe, has a plastic shell. In c128 mode, the built-in 1571 becomes the default LOAD device. All modes on the VIC-IIe are identical to the C64 except that a few more tricks are possible using 2MHz fast mode. The VDC's modes are mildly extendable and mostly don't require active software tricks. []
  6. The c128 DCR, sold in North America, has a metal shell. In c128 mode, the built-in 1571 becomes the default LOAD device. All modes on the VIC-IIe are identical to the C64 except that a few more tricks are possible using 2MHz fast mode. The VDC's modes are widely extendable and mostly don't require active software tricks. []
  7. The SX-64's built–in power supply cannot easily be upgraded. The original PSU does not have enough power for a SuperCPU or a Commodore 17xx REU. The SX-64 can be used with a CMD RamDrive or RamLink, however, as these devices are externally powered. []
  8. All C64s and c128s have a VIC-II. Many visual tricks can be accomplished by using the CPU to manipulate the VIC-II's registers while it is in the process of drawing a frame. []
  9. The c128 and c128 D which have only 16 KB of VDC RAM can be upgraded to 64 KB using a plug-in module or a permanent modification. []
  10. In the C64, the VIC-II has a static ram chip on a dedicated bus for color information. This memory has a 10-bit address bus (for 1024 addresses,) but only a 4-bit data bus (for 16 colors.) The VIC-II uses up to 16 KB of base memory. One of four possible 16K banks of memory the VIC-II can see is selected using b0 and b1 of CIA 2's Port A. []
  11. Like the C64, the VIC-IIe uses a dedicated color RAM chip plus part of base memory, plus there is an extra register in the machine that controls which of the two 1024-nybble segments of color RAM is visible to the VIC. The VIC-II can also access, via a register, the entire 128 KB address space of the c128. []
  12. All C64 and c128 computers feature one SID chip. Additional SID chips can be added, by mapping their registers to unused address space. In theory, there is enough free addressing space for 31 additional SID chips, for a total of 96 voices. In practice, most people add one additional SID, for stereo output and a total of 6 voices, 3 voices per channel. []
  13. The VDC has native support for color cell sizes from 8x2 to 8x32. By using the CPU to manipulate the VDC registers with careful timing, the VDC can display 8x1 color cells. []
  14. The internal RAM upgrades for the c128 are discussed in full detail, including programming information, in articles originally published in the Finnish home computer users' magazine, MikroBITTI, in 1987. The information is now available, in English, here. []