The Retro Elf  Software Library

If your Retro Elf system has been fully decked out with a CPU, expansion and ATA/IDE cards; you probably wish to add a DOS environment to your system. The following is the Retro Elf optimized version of Michael Riley's Elf/OS. You can learn more about the original Elf/OS at Mike's web site at

The following zipped file contains not only the Elf/OS image files, but also included are images for some new Elf/OS enhancements, RCBASICL2, RCFOURTH and SuperBASIC. All the image files are in IntelHex format. There is a PDF manual covering the installation and operation both Elf/OS and SBASIC.

ElfOS-INSTALL-V2B (Updated version)
ElfOS-INSTALL-V2 (Previous version)

NOTE: The above version of this Elf/OS can also be used on a Elf 2K system. Only the real time clock features are not supported given the different RTC hardware used within the Retro Elf hardware.
Super BASIC programs
Here are some Super BASIC programs that I converted from other types of BASIC. All the files are in plain TXT format. This should allow you to use a terminal program like Tera Term to "send file" the text file to your Elf.

23MATCHES - is a strategy game by Bob Albrecht, where each player takes one, two or three matches during their turn. The object is to NOT be the player forced to take the last match.

ACEDUCEY - The Acey-Ducey card game by Bill Palby is where you have to guess if the next card will fall between the first two cards.

ATLANTIS5 - "Escape From Atlantis" is another BASIC text adventure game by Fly.

BANNER - allows create text banners using a serial printer connected to the second serial port on the Retro Elf. The original version of the BANNER program was by Leonard Rosendust.

BANNER2 - is exactly like BANNER above but per-configures the two horizontal and vertical size entries to maximize to an 80 character printer.

DCHARGE - Depth Charge is the classic sub hunt game where you look for a submerene within a 20x20x20 area.

DOGSTAR - is a classic text adventure game  originally by Lance Micklus from the May 1979 issue of SoftSide magazine. I ported it to Super BASIC for a Zenith Z-100 copy.

HEXDUMP - This BASIC program alows you to perfom a he dump the contents of a memory area.

LEM - also known as "Rocket" is a lunar landing simulation. You need to safely land your Lunar Excursion Module (LEM) on the moon.

OREGON76 - Is the original classic version of Oregon Trial from 1976 era. The original programming was by Bill Heinemann back in 1971 with supporting research material by Don Rawitsch.

WORD - is a classic word guessig game where the computer randamly give you a five character word and you have five turns to guess it.
RC BASIC L2 programs
Here are some RC BASIC Level 2 programs that I converted from other types of BASIC. All the files are in plain TXT format. This should allow you to use a terminal program like Tera Term to "send file" the text file to your Elf.

23MATCHES - is a strategy game by Bob Albrecht, where each player takes one, two or three matches during their turn. The object is to NOT be the player forced to take the last match.

BLACKJACK - is a BASIC text version of th classic Black Jack card game.

LETTERS - is a simple but fun game where the computer selects a letter from A through Z. You have to guess what it is within a fixed number of turns. The computer will given clues for each of your guesses.

SLOTS - Produced by Mirabelle and Bob Harper back in 1973, SLOTS is a text version simulation of a slot machine.

TRAP - Originally developed by Steve Ullman back in 1972, TRAP is a game for a random number is generated between 1 and 100. You try to guess two numbers that will trap the random number between it. The computer will give clues on your trap range.

WEREWOLVES1 - is a text based adventure game in BASIC. You have to move through a computer generated world looking to treasure while trying to escape.

WEREWOLVES2 - is a more advanced and harder version of the above WEREWOLVES1.
Some simple 1802 assembly programs
PROGRAM NAME: Walkingbit
DATE: August 2011
BY: Unknown

COMMENT: This short program turn on the most significant LED, delays and then rotates (walks) one LED to the right. Once all eight LEDs are walked through, the program repeats forever.

R0 Program counter.
R1 Delay counter.
R2 Memory pointer to current bit pattern.
0000           E2START: SEX R2      ; Set X to point at R2.
0001 F8 17              LDI PATTERN ; R2 points at RAM location with the PATTERN.
0003 A2                 PLO R2
0004 F8 00              LDI 00h
0006 B2                 PHI R2
0007 FD 00              SDI 00h     ; Set the DF to 1 for start pattern.
0009 52        WALK:    STR R2      ; Save the current bit pattern.
000A 64                 OUT 4       ; Display the pattern.
000B 22                 DEC R2      ; Undo the increment from the OUT command.
000C F8 08     DELAY:   LDI 08h     ; Set delay in R1 to 8 x 256 = 2048.
000E B1                 PHI R1
000F 21        DLOOP:   DEC R1      ; Decrement delay count in R1.
0010 91                 GHI R1      ; If not done with delay do another round.
0011 3A 0F              BNZ DLOOP
0013 02                 LDN R2      ; Rotate the pattern one bit to the right.
0014 76                 RSHR
0015 30 09              BR WALK     ; Do it all again forever.
0017 00        PATTERN: DB 0        ; RAM location of the pattern byte.
DATE: September 1976
BY: Joseph Weisbecker
UPDATED BY: Dave Runkle (for the Retro Elf Version)

COMMENT: This program "think" of a byte, which you must guess in no more than seven tries. When first run, AA (10101010) is displayed. Enter a guess in to the eight toggle switches and cycle the EF4 switch.  If 00 (00000000) is displayed you win. If 01 (00000001) is displayed you are low. If 80 (10000000) is displayed you are high. After sever tries the Q LED is turned on and the secret byte is displayed.
R0 Program counter.
R3 Memory pointer used by display to store data.
R4.0 Number of tries.
RA.0 New secret byte for next game.
RB.0 Current secret byte.

0000 8A     START:    GLO RA            ; Setup secret byte in RB.0.
0001 AB               PLO RB
0002 F8 00            LDI HIGH DISPLAY  ; Set R3 as memory pointer used by
0004 B3               PHI R3            ; the display port.
0005 F8 32            LDI LOW DISPLAY
0007 A3               PLO R3
0008 F8 AA            LDI 0AAh          ; Display AA.
000A 53               STR R3
000B E3               SEX R3            ; Set X to new R3 display pointer.

000C F8 07            LDI 07h           ; Setup the number of tries = 7 in
000E A4               PLO R4            ; R3.0.
000F 64               OUT 4             ; Display "AA" pattern for start.
0010 23               DEC R3            ; Fix memory pointer after OUT.
0011 2A     SECRET:   DEC RA            ; Wait for EF4 press. While looping,
0012 3F 11            BN4 SECRET        ; decrement new secret byte.
0014 37 14            B4 $              ; Wait for EF4 release.
0016 6C               INP 4             ; Get user guess. Put in to D.
0017 8B               GLO RB            ; Compare guess (D) to secret (RB.0).
0018 F5               SD
0019 33 1F            BGE TEST          ; Branch if guess >= secret.
001B F8 01            LDI 01h           ; guess<secret so display 01h.
001D 30 27            BR SHOW
001F 3A 25  TEST:     BNZ OVER          ; Brach if guess > secret.
0021 53     DONE:     STR R3            ; Display.
0022 64               OUT 4
0023 30 23            BR $              ; Stop.
0025 F8 80  OVER:     LDI 80h           ; Guess > secret so display 80h.
0027 53     SHOW:     STR R3            ; Show status.
0028 64               OUT 4
0029 23               DEC R3            ; Fix memory pointer after OUT.
002A 24               DEC R4            ; Decrement tries counter.
002B 84               GLO R4            ; If not out of tries, guess again.
002C 3A 11            BNZ SECURIT
002E 8B               GLO RB            ; Out of tries, show secret.
002F 7B               SEQ               ; and turn on Q LED.
0030 30 21            BR DONE
0032 00     DISPLAY:  DB 0              ; Location of display data.
DATE: Unknown  BY: Unknown
COMMENT: Here is a memory test program for the 1802. It is a bit match type test of the 32K RAM. It doesn't check for cross-talk between the memory address lines. This version does check for data line cross-talk. The LED's will display the current memory page being tested. If there is an error detected the "Q" LED will come on and stay on. If an error is detected the address that caused the error is stored at memory location 0002h (high order) and 0003h (low order).  If there is no errors detected the data LED's will count from "00" to "7F" (01111111) and stop.
R0 Program counter.
R2 Points for memory location where RAM being tested pointer is.
R5 Pointer for value for displayed memory address.
RC Pointer to RAM being tested.
RD.0 Current pattern being tested.

0000 30 05  START:    BR TEST    ; Branch to start of RAM test program.
0002 00               DB 0       ; High order test address pointer.
0003 00               DB 0       ; Low order test address pointer.
0004 00               DB 0       ; High order address to display.
0005 90     TEST:     GHI R0     ; Use program counter to set high pointers.
0006 B2               PHI R2
0007 B5               PHI R5
0008 BC               PHI RC
0009 F8 02            LDI 02h    ; R2 points at memory location where pointer is.
000B A2               PLO R2
000C F8 04            LDI 04h    ; R5 points at current display memory.
000E A5               PLO R5
000F F8 42            LDI 42h    ; RC points a RAM test beginning.
0011 AC               PLO RC
0012 F8 01            LDI 01h    ; RD.0 is current test bit pattern.
0014 AD               PLO RD
0015 9C     TESTL:    GHI RC     ; Update display current test page.
0016 55               STR R5
0017 E5               SEX R5

0018 64               OUT 4      ; Display page.
0019 25               DEC R5     ; Fix pointer after display.
001A EC               SEX RC
001B 9C               GHI RC     ; Update current RAM test location
001C 52               STR R2     ; pointed to by R2.
001D 12               INC R2
001E 8C               GLO RC
001F 52               STR R2
0020 22               DEC R2
0021 8D               GLO R
0022 73               STXD
0023 1C               INC RC
0024 F5               SD         ; Test current RAM pattern.
0025 32 2A            BZ NEXT    ; Jump if current RAM passes.
0027 7B               SEQ        ; Error found turn on Q.
0028 30 28            BR $       ; Stop.
002A 8D     NEXT:     GLO RD     ; Change to next text pattern.
002B FE               SHL
002C AD               PLO RD
002D 3A 15            BNZ TESTL  ; Loop if still more test patterns.
002F 5C               STR RC
0030 F8 01            LDI 01h    ; Reset test bit pattern.
0032 AD               PLO RD
0033 1C               INC RC     ; Move to next page of RAM.
0034 9C               GHI RC
0035 FD 80            SDI 80h    ; Last page?
0037 3A 15            BNZ TESTL  ; If not do another page.
0039 30 39            BR $       ; Stop.