SIMPLE-6802

Features

68B02 CPU
- 1.8432 MHz clock
- MC6802 is fully compatible with MC6800 but without messy two-phase clocking
32KB SRAM
16KB EPROM/EEPROM
- 16KB reserved
- 8KB (28C64 parts can be used)
68B50 Serial Port (ACIA)
- RS-232 port
- Header for FTDI
- 115,200 baud
Reset switch with optional Power Supervisor
95x95mm card
(4) 6-32 mounting holes

Memory Map

0x0000-0x7FFF 32KB SRAM
0x8000-0xBFFF Serial (68B50 ACIA)
0xC000-0xFFFF 16KB EPROM

Chipset

Design

CPU

EPROM

SRAM

ACIA

Headers / Connectors

J1 - RS-232 Serial

DB-9 Male
Pinout

N/C
Receive
Transmit
Loop to pin 6
GND
Loop to pin 4
RTS
N/C
N/C

J2 / J5 - EPROM/EEPROM Select Jumpers

J2 - EPROM Pin 1 jumper
- 1-2 for 28C64, 28C256 (Pull WE to VCC)
- 2-3 for 27256, 27SF256, 27512 (Pull A14 to GND)
J5 - EPROM Pin 27 jumper
- GND (2-3)

EEPROM Pin Table

27512	27256	27SF256	28C256	27128	2764	28C64	PIN	PIN	2764	28C64	27128	28C256	27SF256	27256	27512
A15	VPP	VPP	A14	VPP	VPP	N/C	1	28	VCC	VCC	VCC	VCC	VCC	VCC	VCC
A12	A12	A12	A12	A12	A12	A12	2	27	PGM	WE*	PGM	WE*	A14	A14	A14
A7	A7	A7	A7	A7	A7	A7	3	26	A13	N/C	A13	A13	A13	A13	A13
A6	A6	A6	A6	A6	A6	A6	4	25	A8	A8	A8	A8	A8	A8	A8
A5	A5	A5	A5	A5	A5	A5	5	24	A9	A9	A9	A9	A9	A9	A9
A4	A4	A4	A4	A4	A4	A4	6	23	A11	A11	A11	A11	A11	A11	A11
A3	A3	A3	A3	A3	A3	A3	7	22	OE*	OE*	OE*	OE*	OE*	OE*	OE*
A2	A2	A2	A2	A2	A2	A2	8	21	A10	A10	A10	A10	A10	A10	A10
A1	A1	A1	A1	A1	A1	A1	9	20	CE*	CE*	CE*	CE*	CE*	CE*	CE*
A0	A0	A0	A0	A0	A0	A0	10	19	D7	D7	D7	D7	D7	D7	D7
D0	D0	D0	D0	D0	D0	D0	11	18	D6	D6	D6	D6	D6	D6	D6
D1	D1	D1	D1	D1	D1	D1	12	17	D5	D5	D5	D5	D5	D5	D5
D2	D2	D2	D2	D2	D2	D2	13	16	D4	D4	D4	D4	D4	D4	D4
GND	GND	GND	GND	GND	GND	GND	14	15	D3	D3	D3	D3	D3	D3	D3

J3 - FTDI / TTL Serial

Requires a FTDI cross-over cable

GND
RTS* (out)
+5V
Receive (in)
Transmit (out)
N/C

J4 - 5V Power

2x4 header

First Unit Checkout

Install Sockets

Machined pin sockets

Install Passives

Power

Install 2x4 at J4
Power card via J4 with 5V
Check power pins on parts

Reset

Install U7 Power Monitor
Install pushbutton switch SW1
Reset button gets stretched by Power Monitor U9
Measure reset at 68B02 U5 pin 40

EPROM

SST27C256 EEPROM
- 32 KB part
- Using first 16KB of EEPROM
- J2 EEPROM pin 1 = VPP = VCC or GND
  - Jumper J2:2-3
- J5 EEPROM pin 27 = A14 = GND
  - Jumper J5:2-3
U1 - Do not install MAX232 yet
- Use FTDI connector with FTDI-49MM card

EEPROM Programming

Program using TL-866ii plus programmer
File = SMITHBUG_FORTH_SIMPLE-FC.hex
Part is 32 KB
hex files is 16 KB

Memory Buffer should look like

Got Device ID error
Turn off ID check

Device programmed/verified

Test FTDI Serial

Wiring is not 1:1 to FTDI-49MM
Wire FTDI J3 to FTDI-49MM card
- FTDI-49MM GND pin 1 to J3-1 RX on card
- FTDI-49MM VCC pin 3 to J3-3 RX on card
- FTDI-49MM TX pin 4 on to J3-5 RX on card
- FTDI-49MM RX pin 5 on to J3-4 TX on card
- FTDI-49MM CTS(in) pin 2 to J3-6 CTS on card

>J TO ADDR D000
Forth-68
1 2 + . 3  OK
  OK

Test RS-232 Serial

With MAX232
Install DB-9 Male
Holes don't line up well, but 4-40 screws can fit
Connected to FTDI-49MM and DCE cards
- FTDI-49MM and DCE cards wired together
- DCE has female DB-9
- Separate power cable J2 on FTDI-49MM to J3 on card

Built

Works

Software

SMITHBUG is a debugger similar to MIKBUG
- Examine/Edit memory
- Disassembly code
- Download S record (V2)
- Run code
FIG-Forth - Forth language
Combined SMITHBUG and FIG-Forth build

SmithBUG Builds for SIMPLE-MC6802 CPU Card

Pre-built software

Building Code

Uses a68 assembler
- Command line makes S-Record output
Use srec_cat to shift from EPROM absolute addresses to 0x0000 as HEX file

4KB Build

A68 SMITHBUG_SIMPLE-6802_F000.ASM -l SMITHBUG_SIMPLE-6802_F000.LST -s SMITHBUG_SIMPLE-6802_F000.S
srec_cat SMITHBUG_SIMPLE-6802_F000.s -offset - -minimum-addr SMITHBUG_SIMPLE-6802_F000.s -o smithbug_F000.hex -Intel

8KB Build

A68 SMITHBUG_SIMPLE-6802_E000.ASM -l SMITHBUG_SIMPLE-6802_E000.LST -s SMITHBUG_SIMPLE-6802_E000.S
srec_cat SMITHBUG_SIMPLE-6802_E000.s -offset - -minimum-addr SMITHBUG_SIMPLE-6802_E000.s -o smithbug_E000.hex -Intel

16KB Build

Used with 27SF256 parts
- 2nd half of EPROM unused

A68 SMITHBUG_SIMPLE-6802_C000.ASM -l SMITHBUG_SIMPLE-6802_C000.LST -s SMITHBUG_SIMPLE-6802_C000.S
srec_cat SMITHBUG_SIMPLE-6802_C000.s -offset - -minimum-addr SMITHBUG_SIMPLE-6802_C000.s -o smithbug_C000.hex -Intel

SmithBUG Commands

;	V	VIEW MEMORY
;	E	CHANGE MEMORY
;	I	FILL MEMORY
;	M	MOVE MEMORY
;	D	DISASSEMBLE CODE
;	G	GO TO PROGRAM
;	R	PRINT
;	@	ASCII CONVERSION
;	H	PRINTER ON
;	J	JUMP TO TARGET PROGRAM
;	F	FIND 
;	Q	HARDWARE LOCATION
;	T	TRACE PROGRAM
;	1	BREAKPOINT ONE
;	2	BREAKPOINT TWO
;	K	CONTINUE AFTER BREAK
;	&	S1 LOAD PROGRAM
;	*	HARDWARE LOCATION (TBA)
;	O	ECHO ON
;	N	ECHO OFF

FIGFORTH in RAM

Corsham Tech FIG-Forth 68 page
FIGFORTH GitHub
- Enter command to srecord loader

Using TermTerm, File, Send File
Send fig-FORTH_6800.s19
Type S9 to exit srecord loader
Type J 1000 to jump to address 0x1000
Responds with

Forth-68
1 1 + . 2  OK

FIG-Forth-68 Commands
- Type VLIST to get list og built-ins

TASK   FORTH   NOOP   VLIST   TRIAD   INDEX   LIST   ?   .   D.   D.R   .R   #S   #   SIGN   #>   <#
SPACES   WHILE   ELSE   IF   REPEAT   AGAIN   END   UNTIL   +LOOP   LOOP   DO   THEN   ENDIF   BEGIN
BACK   FORGET   '   R/W   HI   LO   BLOCK_READ   BLOCK_WRITE   ?DISC   -->   LOAD   MESSAGE   .LINE
(LINE)   BLOCK   BUFFER   DR1   DR0   EMPTY-BUFFERS   UPDATE   +BUF   PREV   USE   DABS   ABS   M/MOD
*/   */MOD   MOD   /   /MOD   *   S->D   COLD   ABORT   QUIT   (   DEFINITIONS   VOCABULARY   IMMEDIATE
INTERPRET   DLITERAL   LITERAL   [COMPILE]   CREATE   ID.   ERROR   (ABORT)   -FIND   NUMBER   (NUMBER)
WORD   PAD   HOLD   BLANKS   ERASE   FILL      QUERY   EXPECT   ?STACK   ."   (.")   -TRAILING   TYPE
COUNT   DOES>   <BUILDS   ;CODE   (:CODE)   DECIMAL   HEX   SMUDGE   ]   [   COMPILE   ?LOADING   ?CSP
?PAIRS   ?EXEC   ?COMP   ?ERROR   !CSP   PFA   NFA   CFA   LFA   LATEST   TRAVERSE   -DUP   MAX   MIN
SPACE   ROT   >   <   =   -   C,   ,   ALLOT   HERE   2+   1+   COLUMNS   HLD   R#   CSP   FLD   DPL
BASE   STATE   CURRENT   CONTEXT   OFFSET   SCR   OUT   IN   BLK   VOC-LINK   DP   FENCE   WARNING
WIDTH   TIB   R0   S0   +ORIGIN   B/SCR   B/BUF   LIMIT   FIRST   BL   3   2   1   0   USER   VARIABLE
CONSTANT   ;   :   C!   !   C@   @   TOGGLE   +!   DUP   SWAP   DROP   OVER   DMINUS   MINUS   D+   +
0<   0=   R   R>   >R   LEAVE   ;S   RP!   SP!   SP@   XOR   OR   AND   U/   U*   CMOVE   CR   ?TERMINAL
KEY   EMIT   ENCLOSE   (FIND)   DIGIT   I   (DO)   (+LOOP)   (LOOP)   0BRANCH   BRANCH   EXECUTE   LIT    OK

SMITHBUG and FIGFORTH in ROM

Combines SMITHBUG and FIGFORTH in ROM
- SMITHBUG in ROM from 0xC000-0xCFFF
- FIGFORTH in ROM from 0xD000-0xEFFF
- Vectors are at top of ROM from 0xFFF8-0xFFFF
Fixes in FIG-Forth to get it to run from ROM
- The comments in the file indicated it could be run from ROM but the stack pointed to ORIG which is in ROM
- Fixed addresses of stack and I/O pointer to get it to work from ROM
SMITHBUG and FIGFORTH in ROM GitHub
Assemble

A68 SMITHBUG_FORTH_SIMPLE-6802_C000.ASM -l SMITHBUG_FORTH_SIMPLE-6802_C000.LST -s SMITHBUG_FORTH_SIMPLE-6802_C000.S
6800/6801 Cross-Assembler (Portable) Ver 3.5!
Copyright (c) 1985 William C. Colley, III
fixes for LCC/Windows and improvement by HRJ Aug 26 2019
A68 source_file | -l list_file | | -o/-s object_file |

No Errors

Edit out RAM at top
Make hex file

srec_cat SMITHBUG_FORTH_SIMPLE-6802_C000.s -offset - -minimum-addr SMITHBUG_FORTH_SIMPLE-6802_C000.s -o SMITHBUG_FORTH_SIMPLE-FC.hex -Intel
srec_cat: SMITHBUG_FORTH_SIMPLE-6802_C000.s: 1: warning: no header record
srec_cat: SMITHBUG_FORTH_SIMPLE-6802_C000.s: 1: warning: no header record

Boots to SMITHBUG
Type J D000 to run Fig-Forth or
Type 4 to run Forth

TinyBASIC

TinyBASIC GitHub
TINY BASIC User Manual
- TINY BASIC User Manual PDF
Load using &
- Character/line delays 1 mSec
Send TB_6800.s file
Run using J 0100

27512	27256	27SF256	28C256	27128	2764	28C64	PIN	PIN	2764	28C64	27128	28C256	27SF256	27256	27512
A15	VPP	VPP	A14	VPP	VPP	N/C	1	28	VCC	VCC	VCC	VCC	VCC	VCC	VCC
A12	A12	A12	A12	A12	A12	A12	2	27	PGM	WE*	PGM	WE*	A14	A14	A14
A7	A7	A7	A7	A7	A7	A7	3	26	A13	N/C	A13	A13	A13	A13	A13
A6	A6	A6	A6	A6	A6	A6	4	25	A8	A8	A8	A8	A8	A8	A8
A5	A5	A5	A5	A5	A5	A5	5	24	A9	A9	A9	A9	A9	A9	A9
A4	A4	A4	A4	A4	A4	A4	6	23	A11	A11	A11	A11	A11	A11	A11
A3	A3	A3	A3	A3	A3	A3	7	22	OE*	OE*	OE*	OE*	OE*	OE*	OE*
A2	A2	A2	A2	A2	A2	A2	8	21	A10	A10	A10	A10	A10	A10	A10
A1	A1	A1	A1	A1	A1	A1	9	20	CE*	CE*	CE*	CE*	CE*	CE*	CE*
A0	A0	A0	A0	A0	A0	A0	10	19	D7	D7	D7	D7	D7	D7	D7
D0	D0	D0	D0	D0	D0	D0	11	18	D6	D6	D6	D6	D6	D6	D6
D1	D1	D1	D1	D1	D1	D1	12	17	D5	D5	D5	D5	D5	D5	D5
D2	D2	D2	D2	D2	D2	D2	13	16	D4	D4	D4	D4	D4	D4	D4
GND	GND	GND	GND	GND	GND	GND	14	15	D3	D3	D3	D3	D3	D3	D3

27512	27256	27SF256	28C256	27128	2764	28C64	PIN	PIN	2764	28C64	27128	28C256	27SF256	27256	27512
A15	VPP	VPP	A14	VPP	VPP	N/C	1	28	VCC	VCC	VCC	VCC	VCC	VCC	VCC
A12	A12	A12	A12	A12	A12	A12	2	27	PGM	WE*	PGM	WE*	A14	A14	A14
A7	A7	A7	A7	A7	A7	A7	3	26	A13	N/C	A13	A13	A13	A13	A13
A6	A6	A6	A6	A6	A6	A6	4	25	A8	A8	A8	A8	A8	A8	A8
A5	A5	A5	A5	A5	A5	A5	5	24	A9	A9	A9	A9	A9	A9	A9
A4	A4	A4	A4	A4	A4	A4	6	23	A11	A11	A11	A11	A11	A11	A11
A3	A3	A3	A3	A3	A3	A3	7	22	OE*	OE*	OE*	OE*	OE*	OE*	OE*
A2	A2	A2	A2	A2	A2	A2	8	21	A10	A10	A10	A10	A10	A10	A10
A1	A1	A1	A1	A1	A1	A1	9	20	CE*	CE*	CE*	CE*	CE*	CE*	CE*
A0	A0	A0	A0	A0	A0	A0	10	19	D7	D7	D7	D7	D7	D7	D7
D0	D0	D0	D0	D0	D0	D0	11	18	D6	D6	D6	D6	D6	D6	D6
D1	D1	D1	D1	D1	D1	D1	12	17	D5	D5	D5	D5	D5	D5	D5
D2	D2	D2	D2	D2	D2	D2	13	16	D4	D4	D4	D4	D4	D4	D4
GND	GND	GND	GND	GND	GND	GND	14	15	D3	D3	D3	D3	D3	D3	D3

SIMPLE-6802

Contents

Features

Memory Map

Chipset

Design

Headers / Connectors

J1 - RS-232 Serial

J2 / J5 - EPROM/EEPROM Select Jumpers

EEPROM Pin Table

J3 - FTDI / TTL Serial

J4 - 5V Power

First Unit Checkout

Install Sockets

Install Passives

Power

Reset

EPROM

EEPROM Programming

Test FTDI Serial

Test RS-232 Serial

Software

SmithBUG Builds for SIMPLE-MC6802 CPU Card

Building Code

4KB Build

8KB Build

16KB Build

SmithBUG Commands

FIGFORTH in RAM

SMITHBUG and FIGFORTH in ROM

TinyBASIC

References

Mechanicals

Assembly Sheet

Rev 1

Navigation menu

Search

27512	27256	27SF256	28C256	27128	2764	28C64	PIN	PIN	2764	28C64	27128	28C256	27SF256	27256	27512
A15	VPP	VPP	A14	VPP	VPP	N/C	1	28	VCC	VCC	VCC	VCC	VCC	VCC	VCC
A12	A12	A12	A12	A12	A12	A12	2	27	PGM	WE*	PGM	WE*	A14	A14	A14
A7	A7	A7	A7	A7	A7	A7	3	26	A13	N/C	A13	A13	A13	A13	A13
A6	A6	A6	A6	A6	A6	A6	4	25	A8	A8	A8	A8	A8	A8	A8
A5	A5	A5	A5	A5	A5	A5	5	24	A9	A9	A9	A9	A9	A9	A9
A4	A4	A4	A4	A4	A4	A4	6	23	A11	A11	A11	A11	A11	A11	A11
A3	A3	A3	A3	A3	A3	A3	7	22	OE*	OE*	OE*	OE*	OE*	OE*	OE*
A2	A2	A2	A2	A2	A2	A2	8	21	A10	A10	A10	A10	A10	A10	A10
A1	A1	A1	A1	A1	A1	A1	9	20	CE*	CE*	CE*	CE*	CE*	CE*	CE*
A0	A0	A0	A0	A0	A0	A0	10	19	D7	D7	D7	D7	D7	D7	D7
D0	D0	D0	D0	D0	D0	D0	11	18	D6	D6	D6	D6	D6	D6	D6
D1	D1	D1	D1	D1	D1	D1	12	17	D5	D5	D5	D5	D5	D5	D5
D2	D2	D2	D2	D2	D2	D2	13	16	D4	D4	D4	D4	D4	D4	D4
GND	GND	GND	GND	GND	GND	GND	14	15	D3	D3	D3	D3	D3	D3	D3