DECUS FOCAL8-5 source

Cite as: DECUS FOCAL8-5 source
Original: https://svn.so-much-stuff.com/svn/trunk/pdp8/src/decus/focal8-5/f0005.fc
sha256: 4d8ea34792d833c0dd71748881b1f6972738b2e0e4bbcdbb665a666631d09e09
Version: svn revision 6211
Archived: https://web.archive.org/web/20250421045828/https://svn.so-much-stuff.com/svn/trunk/pdp8/src/decus/focal8-5/f0005.fc
Accessed: 2026-10-20
Licence: none stated; DECUS library program. Quoted here a line at a time.
Credit: Doug Dyment, Digital Equipment of Canada, wrote the program. The so-much-stuff.com PDP-8 archive preserves the DECUS PDP-8 library, crediting Al Kossow, Dave Gesswein and others for scans.
Notes: 2,083 bytes, CRLF line endings; line 1 is blank and line 2 reads "C-FOCAL , 8/68". The live server returned 404 on 2026-10-20, so the file came from the 2025-04-21 Wayback capture; the 2026-04-08 capture is byte-identical, and the directory listing names svn revision 6211. The file is a transcription. It matches the listing printed in the DECUS write-up (decus-focal8-5-writeup), except that the printed line 03.10 reads "D -" where the file has "D 8", and line 03.30 ends "3.6" where the file has "3.8". With the printed "3.6", buying no land would jump past the sale, feeding, and planting to "YOU NOW HAVE NO GRAIN LEFT"; the file's "3.8" goes to the sale. Local copy: .cache/files/decus-focal8-5/f0005.fc.

Cited on

Claims (12)

One person can farm 10 acres, but Ahl's check is strict, so $P$ people may plant at most $10 P - 1$ acres, where Dyment's FOCAL allows $10 P$ .	`f0005.fc L36`	Code
Ahl's BASIC still sets `C` to 0 after a land trade and to 1 after feeding, values nothing reads before the next dice roll overwrites `C`, because in Dyment's FOCAL those lines reset the steward's patience.	`f0005.fc L26f0005.fc L30`	Code
Dyment's FOCAL program starts from the state Ahl kept, 95 people with 5 arriving, 1,000 acres, and 2,800 bushels after a 3,000-bushel harvest at 3 per acre and 200 lost to rats.	`f0005.fc L4`	Code
Dyment's land costs 17 plus a roll of 1 to 5, so 18 to 22 bushels per acre, which matches his write-up's average of "one acre for 20 bushels of grain".	`f0005.fc L18–19f0005.fc L54`	Code
Dyment's program has no term or rating, and after each report it asks whether to continue.	`f0005.fc L14–16`	Code
Starvation in Dyment's program only kills, and no number of deaths ends the game.	`f0005.fc L44`	Code
Dyment's plague halves the population when $⌊ 10 \cdot \| FRAN () \| ⌋ = 0$ .	`f0005.fc L44f0005.fc L8–9`	Code
Dyment's steward has a patience counter, `C`, and when an impossible order finds it below zero, "HAMURABI HAS GONE ON STRIKE" and the game ends.	`f0005.fc L48–51f0005.fc L19`	Code
Ahl's BASIC keeps Dyment's rules for seed, the harvest, rats, arrivals, and food, down to the arrivals formula $c (20 A + S) / P / 100 + 1$ .	`f0005.fc L41–43`	Code
Dyment's DECUS listing already spells the steward's name `HAMURABI`, with one m.	`f0005.fc L46`	Code
Dyment's steward opens each year with "I BEG TO REPORT", and The Sumerian Game reported spoiled grain with "Sir: I am sorry to report".	`f0005.fc L7`	Code
The DECUS listing opens with the line `C-FOCAL , 8/68`.	`f0005.fc L2`	Code