Sharp X1G
 | |
| An office grey X1G Model 30 standing upright (photo: Jun Sasaki, AKIBA PC Hotline!, copyright Impress Corporation) | |
| Specifications | |
|---|---|
| Manufacturer | Sharp Corporation |
| Type | Home computer |
| Released | July 1986[1][2] |
| Intro price | ¥69,800 (Model 10); ¥118,000 (Model 30)[2] |
| CPU | Zilog Z80A, 4 MHz; 80C48 and 80C49 sub-CPUs[2] |
| Memory | 64 KB main RAM; 48 KB graphics VRAM; 10 KB other[2] |
| Storage | Built-in data recorder (Model 10); two 5¼-inch 2D floppy drives, 320 KB each (Model 30)[2] |
| Display | 640 × 200 or 320 × 200, 8 colours; digital RGB and composite video[2] |
| Sound | AY-3-8910 PSG, 3 voices, 8 octaves[2][3] |
| Power | AC 100 V, 50/60 Hz; 24 W (35 W maximum) on the Model 30 rating plate[2][4] |
| Dimensions | 330 × 300 × 135 mm (336 mm wide with feet); keyboard 390 × 185 × 35 mm[2] |
| Weight | 6.0 kg (Model 10); 8.0 kg (Model 30); keyboard 1.3 kg[2] |
| OS / Firmware | — |
| Predecessor | Sharp X1F |
| Successor | X1twin |
| Model no. | CZ-820CB, CZ-820CE (Model 10); CZ-822CB, CZ-822CE (Model 30)[2] |
The Sharp X1G is an 8-bit home computer in Sharp's X1 series, released in July 1986 as the Model 10 (CZ-820C), with a built-in data recorder, and the Model 30 (CZ-822C), with two 5¼-inch floppy drives.[1][2] It has a smaller case than earlier X1s, 33 cm wide instead of 39 cm, which can stand on its side, and it was the first X1 outside the X1turbo range with a composite video output.[2][5] The keyboard is a membrane type, where earlier X1 keyboards were mechanical, and the machine came with a joypad shaped like the Famicom controller.[1][5]
Hardware and software follow the earlier X1s: Oh!MZ's launch report describes it as a new X1 model with more highly integrated circuits, fully compatible with existing X1 software, and it carries the same NEW BASIC (Hu-BASIC V2.0) as the X1F.[2][1]
Models
[edit | edit source]| Model | Part numbers | Storage | Kanji ROM | Weight | Price (1986) |
|---|---|---|---|---|---|
| Model 10 | CZ-820CB (black), CZ-820CE (office grey) | Built-in data recorder | Optional | 6.0 kg | ¥69,800 |
| Model 30 | CZ-822CB (black), CZ-822CE (office grey) | Two 5¼-inch 2D drives, 320 KB each | Fitted (JIS level 1) | 8.0 kg | ¥118,000 |
There was no single-drive X1G, and the Model 30 has no socket for an external floppy drive.[1][6] The Model 10 can take a floppy interface as an option.[2]
Hardware
[edit | edit source]X1 Center's survey of real boards lists these chips for the two X1G models:[3]
| Function | Model 10 (CZ-820C) | Model 30 (CZ-822C) |
|---|---|---|
| IPL ROM | IX0815CE | |
| 8×8 character font ROM | IX0814CE | |
| Kanji ROM | Not fitted | IX0830CE |
| Main-unit sub-CPU | MSM80C49-262 | MSM80C49-277 |
| Keyboard sub-CPU | MSM80C48-14 | |
| CRTC | HD46505SP-2 (HD68B45SP) | |
| Main RAM | 2× MB81464-12 | |
| Attribute and text VRAM | 2× MB8416A-15-SK | |
| PCG RAM | 3× MB8416A-15-SK | |
| Graphics RAM | 6× MB81416-10 (or -12) | 6× MB81416-12 |
| Real-time clock | µPD1990AC | |
| Clock backup battery | None | |
| Sound (PSG) | AY-3-8910 | |
| Sharp custom ICs | IX0831CE, IX0832CE, IX0834CE to IX0837CE | IX0831CE to IX0837CE |
Main memory is two MB81464 chips; the X1F used eight MB8265As.[3] The Model 30's sub-CPU, MSM80C49-277, is the same version that X1 Center lists for the X1F Model 20 and the X1twin.[3]
Floppy drives
[edit | edit source]The Model 30 has two 5¼-inch 2D drives, stacked one above the other, made by ALPS; X1 Center has not identified the model number. Sharp's part numbers for the drive are DMECF0008VE01 and DMECF0008CE00 (black models). The drives have 1 kΩ input terminators, and the drive cable cannot be replaced separately. X1 Center's chip table lists the Model 30's floppy VFO as not yet confirmed.[3][6][5] The drives are 2D only. A disk written in 2D mode on a three-mode drive, such as the CZ-520F or the drives of the X1turbo III and turboZ, may not read in an X1G drive.[7]
Connections
[edit | edit source]The front panel carries, from the lower left, the keyboard jack, two joystick ports, the volume knob, the SYNC MODE switch, the IPL reset and NMI reset buttons, and a long red power button at the right.[5] The rear panel is set about 45 mm into the case so that cables do not stick out; from the left it has digital RGB, TV control, CMT (cassette), video output, printer and audio output sockets, with the two I/O slots and the power switch above.[5][2] On the Model 30 the rear also shows a round vent and an FG terminal, and the video socket is marked M.V. OUT.[4]
The composite output is meant for televisions and video recorders. Set the SYNC MODE switch to B to use it.[2] X1 Center explains that position B brings the timing closer to NTSC and improves the picture, but it shifts the CRTC timing and makes graphics RAM access wait longer.[8]
The keyboard plugs into a 3.5 mm jack that carries +5 V, ground and a one-wire serial signal from the keyboard.[9][1]
Known faults
[edit | edit source]- The X1G has no clock backup battery, so there is no cell to leak.[3]
- Keyboard jacks crack their solder joints on X1 machines; the X1G has a single keyboard jack, on the front panel.[10][5]
- The Model 10's data recorder uses rubber belts; X1 Center's notes on other X1 decks show that these perish.[11]
See the Sharp X1G Troubleshooting Guide for symptoms and checks.
Documentation
[edit | edit source]No scan of Sharp's X1G service manual is on the Internet Archive or X1 Center.[12] Sources for the X1G:
- Oh!MZ, July 1986, pp. 58-61: Sharp's launch specification and a report on the front panel, rear panel and video output.[2]
- 祝一平, 試験に出るX1 (Nihon SoftBank, 1987), a register-level reference for the X1 range.[7]
Repair guides
[edit | edit source]Gallery
[edit | edit source]-
Model 30 standing upright (AKIBA PC Hotline!) -
Front panel controls (AKIBA PC Hotline!) -
Rear panel and rating plate (AKIBA PC Hotline!)
Related pages
[edit | edit source]- Sharp X1F, the model it replaced
- Sharp X1, the first model
- Sharp X1 Turbo
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 X1 (コンピュータ), Japanese Wikipedia—link(accessed 2026-10-21) X1G (July 1986): a case that can stand upright; black (B) and office grey (E); supplied with a cross-key joypad with the X1 logo, like the Famicom controller (CZ-8NJ1); keyboard changed from mechanical to membrane; no one-drive model; the first X1 outside the X1turbo range with a video output socket; Model 10 (CZ-820C) with built-in data recorder, ¥69,800; Model 30 (CZ-822C) with two 5¼-inch 2D drives and without the external FDD interface of the X1F Model 20, ¥118,000. Also: the X1 has only a 1-second periodic interrupt; IPL tries FDD, ROM board and CMT in turn; NMI reset can freeze software.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 Oh!MZ, July 1986, pp. 58-61, feature "新登場X1Gを見る" and table "パーソナルコンピュータCZ-820C/822C仕様": Model 10 (CZ-820C) with a cassette deck and Model 30 (CZ-822C) with two 5¼-inch 2D drives; display television CZ-820D and colour monitor CU-14G announced with it; circuits more highly integrated, giving a smaller case 33 cm wide and 8 cm less deep than the X1F, with the rear panel set about 45 mm into the case; IPL, volume and joystick ports moved to the front; composite "multi-visual" video output, to be used with the front SYNC.MODE switch set to B; the composite picture is a little darker than RGB; no single-drive X1G. Table: main CPU Z-80A (4 MHz), sub-CPUs 80C48 and 80C49; RAM 122 KB (main 64 KB, graphics VRAM 48 KB, other 10 KB); text 80 × 25 or 40 × 25; graphics 640 × 200 one screen (8 colours per dot) or 320 × 200 two screens; kanji ROM optional on the CZ-820C, fitted on the CZ-822C (40 × 12 characters, 3,707 characters including 2,965 JIS level 1 kanji); RGB and composite output; CZ-820C built-in data recorder, CZ-822C two 5¼-inch drives (320 KB per drive); sound 8 octaves, 3 voices; Centronics 8-bit printer port; two Atari-type joystick ports; floppy interface optional on the CZ-820C; dedicated cassette interface on the CZ-822C; two expansion I/O ports; AC 100 V, 50/60 Hz; main unit 330 mm wide (336 mm with feet), 300 mm deep, 135 mm high; keyboard 390 × 185 × 35 mm; weight 6.0 kg (CZ-820C), 8.0 kg (CZ-822C), keyboard 1.3 kg; supplied software: CZ-820C cassette BASIC CZ-8CB01 V2.0 and V1.0; CZ-822C disk BASIC CZ-8FB01 V2.0 and V1.0 and cassette BASIC CZ-8CB01 V1.0. Prices: Model 10 CZ-820CE/B ¥69,800, Model 30 CZ-822CE/B ¥118,000. Scan on the Internet Archive, item OhMZ_1986-07.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 搭載チップセット (chip sets fitted), X1 Center—link(accessed 2026-10-21) CZ-820C (X1G Model 10) and CZ-822C (listed by X1 Center as "X1G M20"): IPL ROM IX0815CE; 8×8 font IX0814CE; kanji ROM IX0830CE on the CZ-822C only; main-unit sub-CPU MSM80C49-262 (CZ-820C) and MSM80C49-277 (CZ-822C); keyboard sub-CPU MSM80C48-14; CRTC HD46505SP-2 (HD68B45SP); main RAM 2× MB81464-12; attribute and text VRAM 2× MB8416A-15-SK; PCG RAM 3× MB8416A-15-SK; graphics RAM 6× MB81416-10 (or -12) on the CZ-820C and 6× MB81416-12 on the CZ-822C; RTC µPD1990AC; no backup battery; PSG AY-3-8910; floppy VFO none (CZ-820C), not yet confirmed (CZ-822C); custom ICs IX0831CE, IX0832CE, IX0834CE, IX0835CE, IX0836CE, IX0837CE, plus IX0833CE on the CZ-822C.
- ↑ 4.0 4.1 Rear panel photograph, File:Sharp X1G Model 30 rear panel.jpg (AKIBA PC Hotline!): rating plate of a CZ-822CE reading AC 100 V, 50/60 Hz, rated power consumption 24 W (35 W maximum).
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 ゲームプレイ画面を録画可能！ X1シリーズで初めてビデオ出力端子を備えた「X1G」– 佐々木 潤 (Jun Sasaki), AKIBA PC Hotline! (Impress), 2019-01-29—link(accessed 2026-10-21) X1G (1986): the drives are stacked vertically instead of side by side as on the X1F; the case is no longer 39 cm wide; it can stand upright or lie flat; front panel from lower left: keyboard jack, two joystick ports, volume knob, sync mode switch, IPL reset, NMI reset, and at the right the power switch, a long red button; first X1 with a video output; keyboard changed from mechanical to membrane; supplied with an X1-logo joypad like the Famicom controller; rear panel recessed, from left: digital RGB, TV control, CMT, video output, printer port, audio output, with the I/O slots and power switch above the printer and audio sockets; feet on the left side for standing it upright: loosen the screw slightly, spread the foot and tighten again; Model 10 with a high-speed electromagnetic data recorder and Model 30 with two drives, in black or office grey, ¥69,800 and ¥118,000.
- ↑ 6.0 6.1 X1/turbo/Zシリーズ搭載FDDインターフェース仕様, X1 Center—link(accessed 2026-10-21) CZ-822C (listed as "X1G M20"): no 2HD, FM or DMA; no external expansion FDD connector; internal drive cable not replaceable. Drives: CZ-822CB (black bezel) and CZ-822CE (office grey), 5¼-inch 2D × 2, ALPS make, model not identified, Sharp part DMECF0008VE01 / DMECF0008CE00 (black); the X1G drive has a 1 kΩ terminator, step rate and power-on restore not confirmed.
- ↑ 7.0 7.1 祝一平 (Iwai Ippei), 試験に出るX1 ハードウェアのフルコース (Nihon SoftBank, 1987), p. 217: 2D disks written on 2D/2DD/2HD drives (CZ-520F, X1turbo III and turboZ internal drives) are not guaranteed to read on 2D-only drives such as the internal drives of the X1G, X1turbo and X1turbo II and the CZ-800F, 801F and 502F. Scan on the Internet Archive, item SHARPX1TecRef.
- ↑ X1/turbo/Zシリーズ拡張コネクター等一覧, X1 Center—link(accessed 2026-10-21) Composite video output (X1G and X1twin): NTSC composite for monitors without RGB input, separate from the telopper of the turbo and Z; switching SYNC to B brings the timing close to NTSC and improves the picture, but the CRTC timing shifts and graphics RAM waits increase. Keyboard and other connectors listed for the whole range.
- ↑ 佐藤 達之 (Sato Tatsuyuki), SHARP X1/X1Turbo キーボード端子 通信仕様 Ver 0.1, 2001, X1 Center, x1kbd.pdf, p. 1: one-wire serial from keyboard to main unit only; 3.5 mm stereo mini jack, +5 V on the tip, the transmit signal on the ring, ground on the sleeve.
- ↑ キーボードコネクタの半田剥離, X1 Center—link(accessed 2026-10-21) Keyboard connector solder cracks are one of the most frequent faults on X1, turbo and Z machines.
- ↑ CZ-800Cカセットデッキの修理メモ, X1 Center—link(accessed 2026-10-21) Cassette decks deteriorate with age, and some butyl-type rubber parts melt into a sticky mass; most deck faults are cured by replacing the belts and rings.
- ↑ 図面資料, X1 Center—link(accessed 2026-10-21) Schematics hosted: CZ-800C (X1), CZ-850C/851C/852C (X1turbo), CZ-8RL1. No X1G schematic.