The 128 Remixes: Commodore 256, 128D/81, 128DL, 128CR
aka 128/D81, 128D81, Kentron
Introduced Never officially. May have been developed around 1986 or 1987.
Hardware Identical to the plastic-case 128D; integrated 1563 3.5" disk drive.
Graphics and Sound Identical to the 128D.
Eventual Fate Scrapped prototype. Some models are known to exist.
The 128D/81 designation is not the name the unit shows (the unit has no name stamped on it at all); I've simply used Jim Brain's name for the unit in the Canonical Commodore Products List for consistency. According to Bo Zimmerman, the "KENTRON" designation turns up on early 128Ds as well (his has a paper label with the same name). When he asked Bil Herd about it, Bil said it was a "Japanese location that worked with CBM Tokyo, owned by CBM."
Unlike the DL units, the other 128s with integrated 3.5" drives, the 128D/81 is actually made from injection-molded plastic, meaning that Commodore was at least halfway serious about producing the unit.
Al's unit above is essentially a heavily modified 128D (not DCR) with a large number of development daughterboards grafted on, particularly for the VIC-IIe and MMU, so this unit was clearly not finished. One particularly grotesque feature are the external (!) ports on the 1563, which was obviously a standalone unit (complete with power receptable, power switch, serial ports and all) that was stripped of its original case and shoved inside. It also has a 1581 ROM in it!
See the DL for additional comments.
The 256 is undoubtedly a descendent of the D/81.
See the DL for additional comments.
Introduced Never officially. May have been developed simultaneously
with the 128D/81.
Hardware Flat 128 (or possibly 128CR) with integrated 3.5" drive in various positions envisioned but all models eventually released in liquidation are dummy mockups with non-functional electronics and milled (not production plastic) casings.
Graphics and Sound Presumed identical to the 128.
Eventual Fate Never completed. Known liquidated models all non-functional models or mockups.
The three prototypes shown above are probably chronologically ordered with Prototype 2, since it has the most integrated design, being the final one. 1 and 3, both pop-up drives, appear to be variations on the other, possibly as simple as a hinged section of the case under which the drive fit.
Since the D/81 is a working unit, and these are not, it is possible that the DLs may have been forerunners of that unit. What is unusual, though, is that the port views show actual ports and connectors, so there must have been some sort of mainboard (even if merely a mockup). There is an additional 'Floppy Disk Drive' port shown, possibly for a mythical TCBM or Shugart drive (the 1563?), but the others are bog-standard, including the user port and expansion port.
Thanks to Nicolas Welte for the report. First, some background: the 128DCR (D Cost Reduced) is the American version of the 128D, the most obvious difference being the metal case on the DCR and the plastic one on the D. Internally, the D has the flat 128 chip set (NMOS SID) and 16K VDC RAM, with the 1571 on a separate board; the DCR has an integrated board, all HMOS components, and the 1571 and 128 boards unified into a single PCB. The D is unknown in the States, although the DCR did appear in some internationalised remixes in very small quantities in Europe.
The CR, thus, is a flat 128 but with the DCR chipset and 64K VDC RAM, a logical release to allow Commodore to phase out the old 65xx NMOS chips once and for all and save money on manufacturing processes since the boards, except for the obvious lack of the 1571 in the CR, are practically identical. Jim Brain lists a flat 128 with 64K VDC RAM in the Canonical List, which is undoubtedly the same unit.
One other important difference between the DCR and D models is the VDC chip used. The earlier 8563 appeared in the original flat 128 and the D; the DCR has the later 8568 with a dissimilar pinout and programmable h-sync and v-sync polarities. Nicolas has been able to coax a 21kHz signal out of the 8568 that allows the 128 to display EGA, albeit verrrrry slowly. Which one the CR has is not certain, but it is most likely the 8568.