Sharp X68000 ACE
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| A black X68000 ACE with its keyboard, a Sharp monitor and the mouse, at the 2025 Micom Show (photo: Darklanlan, CC BY 4.0) | |
| Specifications | |
|---|---|
| Manufacturer | Sharp |
| Type | Personal computer |
| Released | March 1988[1] |
| Intro price | ¥319,800 (ACE); ¥399,800 (ACE-HD)[2] |
| CPU | Hitachi HD68HC000 at 10 MHz[2] |
| Memory | 1 MB[1] |
| Storage | Two 5.25-inch 2HD floppy drives; 20 MB hard disk in the ACE-HD[1][2] |
| Display | — |
| Sound | — |
| Power | 100 V AC[2] |
| OS / Firmware | — |
| Successor | Sharp X68000 EXPERT |
| Model no. | CZ-601C (ACE), CZ-611C (ACE-HD) |
The Sharp X68000 ACE (CZ-601C) and ACE-HD (CZ-611C) replaced the original Sharp X68000 in March 1988.[1] They keep the twin-tower case, rearrange the rear connectors, add a front switch that forces a stuck floppy disc out, and make room for a hard disk inside the case; the ACE-HD has a 20 MB disk fitted.[2]
The power supplies are not the same as the later machines': the ACE uses the type owners call the SH2 and the ACE-HD the SH3, where the EXPERT, SUPER, XVI and X68030 all use the SH4.[3] Neither Sharp's service manual nor a full capacitor list has been published for the ACE's boards or supplies. Poe, a Japanese repairer, has written up ACE and ACE-HD repairs: a leaking nickel-cadmium cell on the control board, a leaking SH2 supply and the floppy drives.[4]
History
[edit | edit source]Sharp put the ACE on sale in March 1988 at ¥319,800 and the ACE-HD at ¥399,800, in grey or black.[1][2] The Sharp X68000 EXPERT replaced them in March 1989 with 2 MB of memory as standard.[1][2]
Hardware
[edit | edit source]Boards
[edit | edit source]Poe lists the ACE's main board as K5709DE, the control board in the base as K5710DE and the analogue board as K5711DE. The nickel-cadmium backup cell is on the control board.[4] The CPU is Hitachi's HD68HC000 at 10 MHz, and 1 MB of memory is standard; a second megabyte goes on the main board on a dedicated memory board, which has to be fitted before any larger expansion.[2]
Power supplies
[edit | edit source]The ACE's SH2 and the ACE-HD's SH3 run from 100 V mains.[3][2] Poe's supply table notes that the SH2 has C9 at 390 µF 180 V and C40 and C41 at 3900 µF 10 V, different capacitances from the later SH4, and that SH2 boards exist in yellow paper-epoxy and green glass-epoxy versions, with no replacement main connector available.[5] kunichiko has published in-circuit resistance readings for an SH3 from an ACE.[3] The tower models have a main switch on the rear as well as the front switch.[2]
Floppy drives
[edit | edit source]The ACE introduced the K61432-72 drive, which Sharp went on using in the tower models up to the X68030; the original model's K-61432-71 was made for that model only.[6] From the ACE onwards a stuck disc is forced out from the front of the machine; the original model has its forced-eject button on the rear.[2][7]
Known problems
[edit | edit source]- Leaking nickel-cadmium cell: on Poe's ACE the cell on the control board had leaked, the metal terminals were corroded almost through, the contacts had green corrosion, and pins 1 to 4 of the Motorola MC68901P beside it had rusted, so he replaced that chip.[4]
- Leaking power supply capacitors: Poe photographed leakage on an SH2 board.[4]
- Floppy drives: capacitors and grease. After servicing the drives of an ACE-HD, Poe found drive 0 ejecting discs without reading them, and had not found the cause when he wrote.[4]
Repair guides
[edit | edit source]- Sharp X68000 ACE General Maintenance
- Sharp X68000 ACE Troubleshooting Guide
- Sharp X68000 ACE Capacitor Replacement Guide
Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 X68000, IPSJ Computer Museum, Information Processing Society of Japan—link(accessed 2026-10-21) The X68000 ACE and X68000 ACE-HD went on sale in 1988. Series table: X68000 ACE, CZ-601C, March 1988, 1 MB; X68000 ACE-HD, CZ-611C, 1 MB, 20 MB hard disk; SASI hard disk interface on the earlier models.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 X68000, Wikipedia (Japanese)—link(accessed 2026-10-21) Model table: ACE CZ-601C ¥319,800 and ACE-HD CZ-611C ¥399,800 (20 MB), March 1988, grey or black (-GY/-BK), tower, 1 MB; rear I/O layout changed; forced floppy eject from a front switch added; hard disk model added. From the ACE onwards there is space for a hard disk inside the case. The original model, ACE, EXPERT and SUPER use Hitachi's HD68HC000 at 10 MHz. The original, ACE, PRO and PRO II have 1 MB as standard; a second 1 MB goes on the main board on a dedicated memory board, which has to be fitted before more memory is added. The tower models have a main power switch on the rear; 16 KB battery-backed SRAM keeps the memory switch settings.
- ↑ 3.0 3.1 3.2 X68000シリーズ電源のハンダ面から見た抵抗配置図– Kunihiko Ohnaka (kunichiko), 2020-10-10—link(accessed 2026-10-21) Supply by model, quoted from Poe: ACE (CZ-601C) SH2; ACE-HD (CZ-611C) SH3; EXPERT, EXPERT II, SUPER, XVI and X68030 SH4. The author owns an SH3 from an X68000 ACE and gives its in-circuit resistance readings measured from the solder side.
- ↑ 4.0 4.1 4.2 4.3 4.4 X68000 ACE/ACE-HD CZ-601C CZ-611C / FDDユニット K61432-72 / 電源 SH2･SH3 修理– Poe, 2021-01-20—link(accessed 2026-10-21) Parts of the CZ-601C: control board (base) K5710DE with the nickel-cadmium cell; main board K5709DE; analogue board K5711DE. Photographs: ACE-HD SH3 supply; SH2 supply board with visible leakage; control board with the leaked cell, terminals corroded almost to breaking and contacts with green corrosion; after removing the cell and capacitors, rust on pins 1 to 4 of the Motorola MC68901P, which was replaced; the leak's extent and broken tracks are checked after removing the cell. ACE-HD drive K61432-72, version 02: the spindle motor is easy to remove; capacitors replaced and re-greased; afterwards drive 0 ejected discs without reading them, cause not found.
- ↑ SHARP X68000 修理– Poe—link(accessed 2026-10-21) Power supply table: CZ-601C ACE, SH2: C9 180 V 390 µF, C40/C41 10 V 3900 µF, "the capacitance is different but it can be used"; yellow (paper-epoxy) and green (glass-epoxy) boards exist; no replacement main connector. CZ-611C ACE-HD: SH3.
- ↑ SHARP X68000 FDD K61432-71 K61432-72 K-61435-72 修理– Poe, 2020-02-23—link(accessed 2026-10-21) Four broad kinds of X68000 drive: K-61432-71 for the original model only, K-61432-72 used from the ACE onwards (later K-61435-72), one for the PRO and PRO II, and the 3.5-inch drive of the Compact models. Capacitor lists for versions 03, 04 and 07 of the K-61432-72; capacitors under the spindle motor and on the motor driver board found leaking; do not remove the spindle or stepping motor just to change capacitors.
- ↑ Sharp, X68000 取扱説明書 for the CZ-600C (File:Sharp X68000 CZ-600C Owner's Manual.pdf), 6.3, printed page 42 (PDF page 56): the DISK EJECT button on the rear forces a disc out.