ZPI
Retrofitting a broken Zeos Notebook 386 with a raspberry pi and custom mainboard
DEV - Development Prototypes
DEV KBD+RTC
Modules
Planned modules for the main board, to replicate all of the functionality of the original device.
KBD - Keyboard
Duties
Convert the stock keyboard into USB
Parts
- Teensy 4.1
- Original Keyboard
References
Keyboard Matrix
@ Connector Top Down
B D F H J 2 4 6 8 X
A C E G I K 1 3 5 7 X X
----------- -----------
1 3 5 7 X X A C E G I K
2 4 6 8 X B D F H J
| A | B | C | D | E | F | G | H | I | J | K | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | ` ~ | F1 | F3 | 5 % | F5 | 7 & | F10 | F8 | Rshft | LArr | - |
| 2 | Esc | LCtrl | F2 | F4 | Spc | F6 | F9 | F7 | \ | | DArr | - |
| 3 | 1 ! | Fn | 3 # | 4 $ | 6 ^ | 8* | 9 ( | RCtl | - | UArr | - |
| 4 | Tab | Z | LAlt | T | Ent | U | 0 ) | RAlt | + = | N | Del |
| 5 | Fn? | LShft | E | R | M | I | O | [ { | ' " | RArr | - |
| 6 | Cap | 2 @ | D | F | B | . > | P | F11 | - _ | Num | Scl |
| 7 | Q | W | X | G | Y | K | ; : | H | F12 | Back | Ins |
| 8 | A | S | C | V | J | L | / ? | , < | ] } | PrSc | Pas |
RTC - Realtime Clock
Duties
- Emulate a DS1307 real time clock chip
- Optionally implement extra ram set/recall
- Optionally implement DS3231 alarms, temperature
Parts
- Reuse the Teensy 4.1 that's handling Keyboard input
- CR1220 Battery (recycled from 380XD repair)
PWR - Power Supply
Duties
- Provide +5v power to the computer
- Provide charging current for the Ni-Cd battery
- LED outputs for Power on, Battery Present, Charging, Charge complete
Parts
- LM2576 (TI?, 3A?) lm2576hv.pdf
- ATTiny84 Ni-Cd Monitor ATtiny24A-44A-84A-DataSheet-DS40002269A.pdf
- Based on Freescale MC68HC908QY4A Example AN2679.pdf AN3392.pdf
CPU - Computer
Duties
Actually handle the computer parts of the computer
Parts
Either (Depending on need for HDMI and PCI)
- Raspberry Pi Compute Module 3
- Raspberry Pi Compute Module 4
DSK - Floppy Disk Drive
Duties
Map the physical floppy drive to usb
Parts
- TEAC FD-335HF 26-pin floppy drive
- Arduino Compatible Microcontroller
Drive References
| Pin | Signal | Pin | Signal |
|---|---|---|---|
| 1 | +5V | 2 | Index |
| 3 | +5V | 2 | Drive Select |
| 5 | +5V | 2 | Disk Change |
| 7 | NC | 2 | Ready |
| 9 | HD OUT | 2 | Motor On |
| 11 | NC | 2 | Direction Select |
| 13 | NC | 2 | Step |
| 15 | GND | 2 | Write Data |
| 17 | GND | 2 | Write Gate |
| 19 | NC | 2 | Track 00 |
| 21 | NC | 2 | Write Protect |
| 23 | GND | 2 | Read Data |
| 25 | GND | 2 | Side One Select |
LCD - Built-in Display
Path One: Keep the current LCD
Duties
If recycling the current LCD, will need to ensure proper power is available and do one of two things:
- Convert the video signal from HDMI to 4-bit monochrome LCD signal
- Write a driver that is similar in structure to SPI/I2C framebuffer to output compatible signal
Pros
- Less hardware to purchase
- Keep original aesthetic
Cons
- Difficult to get awkward and high voltages to run CFL backlight
- Have to reverse engineer old 4-bit signal standard (Documentation is minimal, but looks to be comparable to VGA)
- Writing a god damn video driver
Path Two: Use a new LCD
Duties
If using a new off-the-shelf LCD, will need to find something that will fit inside of the current case.
- Curent screen: 4:3 ratio, 9.5" diagonal, 7.6" width , 5.7" height
- 16:9 screen: 11.6" diagonal, 10.1" width, 5.7" height
- 16:10 screen: 10.8" diagonal, 9.1" width, 5.7" height
Pros
- Much easier to just use HDMI/VGA and 12v power
- Brighter, easier to see
- Color!
Cons
- Damn near impossible to find modern LCDs that are the proper size
- Will need to make custom mounting hardware for the screen
- Price of a new LCD is slightly more than I'd like to spend
VGA - Video Output
PCI - Parallel and Serial Ports
Duties
Make available the original type of ports the original device had, in roughly the same positions
These ports consist of:
- 1 Parallel Port
- 1 External 9-pin Serial Port
- 1 Internal Serial Port, for the modem
Parts
While still undecided, some candidates are available.
- ASIX MCS9901 PCIe to Dual Serial and Single Parallel Controller
- Prolific PL2303GC USB to Full UART IC
- Prolific PL-2303HX USB-Serial Bridge
- WCH CH340 USB-Serial chip
MDM - Bluetooth Modem
Duties
Have a way to allow the computer to "dial in" to a network using bluetooth, and a OpenWRT "base station". Optionally, have the board be designed to use a similar connector, layout, and size of the original modem, so that this part can be used by others with compatible boards.
Parts
- HC-05 Bluetooth to Serial Port module