The Sharp PC-E220 Homepage

Programming Languages:: Basic, Z80-Assembler
Ram:: 32 kB with 30090 bytes free usable (addresses 0100-77E0)
Rom:: 128 kByte (1 Mbit-Rom) contains 8* 16 kB banks (addresses 8000-BFFF, C000-FFFF)
CPU:: CMOS-SC7852 (Z80A code-compatible, not cycle-compatible), 3.58 MHz (3579545 Hz)
Display:: 4 lines x 24 characters, resp. 144 x 32 pixel (contrast manual adjustable)
Keys:: 82
Sound:: frequency, duration and number adjustable
Interface:: 11 pin interface (SIO (max. 9600 baud), printer, cassette)
Size:: 215 x 100 x 18 mm
Weight:: 300 g with batteries and hard case (280 g without both)
Operating temperature: 0 C - 40 C
Power:: four 1.5 V batteries (AA resp. R06), one 3 V CR-2032 lithium battery
Build:: 1991

Versions

Three different versions, V.0, V.1 and V.2, exist which differ slightly in the ROM contens and probably even in the hardware, e.g. the CPU clock. See also the remark in the last paragraph in section Rom banks.

Power

Obviously, it can be supplied by four 1.5 V AA batteries. But you can also use the calculator with a power supply of 4 - 6 V voltage! It must be connected to pin 2 (Vcc) and pin 3 (ground) of the 11-pin interface. Take care of the right polarity. The typicall power consumption is about 0.37 W.

The 11-pin Interface

This is a 2.54mm pin-head and let the pins be numbered from 1 (left) up to 11 (right) if looking at the interface at the Sharp PC-E220
(left the LCD display above the lower numbered pins and right the keys above the high numbered pins).
One can use a RS-232 protocol with 5V (high) and 0V (low) logic to make seriel input/output:

Sharp direc  RS232   Sharp
 pin   tion   name    name    meaning
---------------------------------------------------------------------------
   1    out     ?      BUZ    buzzer signal
   2     -     Vcc     GND     5V
   3     -      SG     Vcc     0V   signal ground
   4    out    CTS     BUSY   (Sharp signals it is busy)
   5    out    DTR     DOUT   if high then Sharp has activated the interface
   6    in     RXD     XIN    Sharp reads data in
   7    out    TXD     XOUT   Sharp sends data out
   8    in     DRS     DIN
   9    in     RTS     ACK    must be high to signal Sharp that it may send data
  10     -      -       -     not connected
  11     -      -       -     not connected

Because usually RS-232 computer levels are between 3 V and 15 V if high and between -15 V and -3 V if low (the range between -3 V and 3 V is dead range for noise absorption), you will need a level converter, which e.g. double respectively half the signal voltages from TTL/CMOS resp. RS232. Also input voltages significantly larger than 6 V may destroy the Sharp pocket computer!

Signal levels:

RS232 Inverted CMOS Sharp IO
-12 V 0 V 5 V
+12 V 5 V 0 V

Using a 9-pin RS-232 D-Sub male plug-in
you must connect

RS232	Inverted CMOS	Sharp IO
-12 V	0 V	5 V
+12 V	5 V	0 V

RXD (pin 2 of RS-232D) with pin 7 INVERTED of Sharp,
TXD (pin 3 of RS-232D) with pin 6 INVERTED of Sharp,
SG (pin 5 of RS-232D) with pin 3 of Sharp,

should connect

RTS (pin 7 of RS-232D) with pin 4 INVERTED of Sharp,
CTS (pin 8 of RS-232D) with pin 9 INVERTED of Sharp,

and might connect

DTR (pin 4 of RS-232D) with pin 8 INVERTED of Sharp,
DSR (pin 6 of RS-232D) with pin 5 INVERTED of Sharp,

The data transmission will be in the Intel Hex-format with a default byte count of 16 bytes data resulting in a record length of about 43 characters (depends on CR/LF) each Intel Hex-line. Field type is always 0 except the last record which has type 1. If you transmit code to the Sharp then be sure that you make a pause of at least 0.1 sec after each Intel Hex-line, because the Sharp needs a bit of time to check and decode the data bytes!

LCD Display

The display is made up of two separate panels, each 32x72 dots sized. It is driven by a HD62202 and a HD61203 chip.

Existing Ports

Port	I/O	usage	used bits	comment
10	in	key input	01234567	returns column vector of a 8x8 resp. 8x2 matrix
11	out	key strobe	01234567	either 0 or choose row of 8x8 matrix via a 1-bit mask for port 10
12	out	key strobe	01______	either 0 or choose row of 8x2 matrix via a 1-bit mask for port 10
13	in	key board	0_______	lowest bit indicates status of SHIFT key
14	in/out	timer	0_______	lowest bit indicates timer signal. This is the clock from the LCD driver which has a period of about 0.95 sec
15	in/out	11 pin interface	0______7	Bit 0 is cleared and Bit 7 indicates pin XIN input enabled/inhibited
16	in/out	interrupt handling	0123____	asks/clears the 4 interrupt reasons: Bit 0 keyboard, Bit 1 ON-Key, Bit 2 timer, Bit 3 CPU-pin INT
17	out	interrupt handling	0123____	enables/disables 4 interrupt sources: Bit 0 keyboard, Bit 1 ON-Key, Bit 2 timer, Bit 3 CPU-pin INT
18	out/in	11 pin interface	01_____7	Bit 0 pin BUSY/CTS, Bit 1 pin DOUT, Bit 7 XOUT/TXD (complement of data bit)
19	in/out	bank mapping	012_____	adress range C000-FFFF: valid values: 0-7; one of eight banks of internal ROM is selected, current value stored at 7900H
	in/out	bank mapping	____456_	adress range 8000-BFFF: if Bit 6 is set then Bits 4 and 5 address one of four possible 16 kB ROMs on the expansion port
1A	out			only cleared when BASIC module init
1B	out	bank mapping	__2_____	if Bit 2 is set, an external 32 kB RAM on the expansion port is mapped to 0000-7FFF (cleared when BASIC module init)
1C	out	peripheral reset	01______	Bit 0 indicates trigger status and Bit 1 whether low or high signal is supplied
1D	in	battery status	0_______	Bit 0 indicates battery status
1E	out		01______
1F	in	11 pin interface	012_____	Bit 0 pin DIN, Bit 1 pin ACK/RTS and Bit 2 pin XIN/RXD (complement of data bit)
	in	key board	_______7	Bit 7 indicates status of ON- resp. break- key
58	out	LCD-control	01234567	value: column*4+row \| 40 , 0 <= column < 24, 0 <= row < 4
59	in	LCD-control	_______7	Bit 7 indicates busy
5A	out	LCD-data	01234567	each byte represents 8 successive pixels in a column
5B	in	LCD-data	01234567	each byte represents 8 successive pixels in a pixel column

Rom Banks

V.1	V.2	comment	User key
0		System/BIOS always at 8000-BFFF
1		Basic Interpreter (mapped default at C000-FFFF)	BASIC
2		Peripherial CE-126P (Printer/Cassette) (what still? calculator?)
3		Text Editor / Monitor	TEXT
4		Statistics & Fonts	STAT
5	5	Assembler / Diagnostic modul	ASMBL
6	6	Engineer Software (Integration, Trigonometry, Physical Constant)	ENG
7	7	Engineer Software (Factorization, Metric Conversion, Greek, Complex number)	ENG

Version .1 and .2 of bank 5 differs only in 3 byte positions.
If both keys SHIFT and , (colon) are pressed during RESET is done
then 5 diagnostic modi are selectable (caution, RAM-Check clears total memory !).
Moreover then the ROM-version, one of V.0, V.1 or V.2, will be displayed.

Software limitations

calculation precision: 10 digits + 2 digits exponent (value range: < +- 1.0e100)
maximal depth of nested parenthesis: 15
Basic interpreter:
- subroutine stack: maximal 10 nestings
- function stack: maximal 16 nestings
- for-next-loop stack: maximal 5 nestings
- data stack: maximal 8 buffers

Resources

list of all BASIC key words with their byte code and short explanation
valid Basic codes
helpful transmission and conversion C-sources running under Linux
First 256 bytes of RAM in Intel Hex-Format
System RAM 7800-7FFF after reset
RAM usage
ROM addresses and Entry points
40 pin expansion bus definition
LCD character font (5x7)
Key-codes
memory mapped LCD symbols
the 1S timer signal
system routine "character(s) output to LCD"
system routine "character input from keyboard"
Looking at the battery case and the contrast wheel
The opened battery case
A 40 signal width expansion bus can be accessed (double sided, 26.4 mm width (1.27 mm spacing), 5V CMOS-level)

External Links

Short Basic manual
Z80-ASM C-Source code of a great Z80-monitor and Assembler for Linux.
private collection
Sharp Pocket Calculators
PC-E220
PC-E220
selfmade interface cable
Home compmuseum
11polige Schnittstelle
the Japanese predecessor PC-E200
Japanese Pocket PC museum

Achim Flammenkamp
2010-04-16 19:48 UTC+2