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 USB - USB Hub and Devices