The report becomes next year’s starting point. Add population growth, a year counter and an ending, while keeping land fixed at 100 acres for now.
Replace lines 530, 4140.
Add lines 450, 460, 540, 550, 4110, 4150, 5000, 5010, 5020, 5030, 5040, 5050, 5060, 5070, 5080, 5090, 5100, 5110, 5120, 5130, 5140, 5150, 5160, 5170.
450 IF deaths=0 THEN LET newcomers=INT (pop/20)
460 LET pop=pop+newcomers
530 IF k$<>" " THEN GO TO 500
540 IF yr=10 OR pop=0 THEN GO TO 5000
550 LET yr=yr+1: GO TO 220
4110 PRINT AT 15,1;"Newcomers: ";newcomers
4140 PRINT AT 19,1;"SPACE continues. R restarts."
4150 PRINT AT 20,1;"Q quits."
5000 CLS
5010 PRINT AT 2,10; INK 6; BRIGHT 1;"YEARFALL"
5020 PRINT AT 5,2;"Years completed: ";yr
5030 PRINT AT 7,2;"People: ";pop;" (started at 60)"
5040 PRINT AT 8,2;"Grain: ";grain
5050 PRINT AT 9,2;"Land: ";land
5060 PRINT AT 11,2;"People lost over run: ";lost
5070 LET m$="A settlement still standing."
5080 IF lost=0 THEN LET m$="Nobody has starved."
5090 IF lost=0 AND grain>=3*pop THEN LET m$="Growing, with grain in reserve."
5100 IF pop=0 THEN LET m$="The settlement is empty."
5110 PRINT AT 14,1; INK 6;m$
5120 IF pop>0 THEN PRINT AT 16,2;"Next year's food: ";3*pop
5130 PRINT AT 19,1;"R new settlement. Q quits."
5140 GO SUB 8000
5150 IF k$="q" OR k$="Q" THEN STOP
5160 IF k$="r" OR k$="R" THEN GO TO 200
5170 GO TO 5140Complete source at this checkpoint
10 BORDER 0: PAPER 0: INK 7: CLS
140 RANDOMIZE
200 LET pop=60: LET grain=360: LET land=100: LET yr=1: LET lost=0
220 LET feed=3*pop
230 IF feed>grain THEN LET feed=grain
240 LET plant=land
250 IF plant>2*INT (feed/3) THEN LET plant=2*INT (feed/3)
260 IF plant>grain-feed THEN LET plant=grain-feed
270 GO SUB 2000
300 GO SUB 8000
310 IF k$="q" OR k$="Q" THEN STOP
320 IF k$="r" OR k$="R" THEN GO TO 200
340 IF k$="f" OR k$="F" THEN LET edit=2: GO SUB 6000: GO TO 270
350 IF k$="p" OR k$="P" THEN LET edit=3: GO SUB 6000: GO TO 270
360 IF k$<>" " OR ok=0 THEN GO TO 300
400 LET oldpop=pop: LET oldgrain=grain: LET oldland=land
410 LET grain=left
420 LET deaths=pop-fed: LET lost=lost+deaths: LET pop=fed
430 LET crop=2+INT (RND*4): LET harvest=plant*crop: LET grain=grain+harvest
440 LET newcomers=0
450 IF deaths=0 THEN LET newcomers=INT (pop/20)
460 LET pop=pop+newcomers
470 GO SUB 4000
500 GO SUB 8000
510 IF k$="q" OR k$="Q" THEN STOP
520 IF k$="r" OR k$="R" THEN GO TO 200
530 IF k$<>" " THEN GO TO 500
540 IF yr=10 OR pop=0 THEN GO TO 5000
550 LET yr=yr+1: GO TO 220
2000 LET fed=INT (feed/3)
2010 IF fed>pop THEN LET fed=pop
2020 LET left=grain-feed-plant
2030 LET ok=1: LET m$="All fed. Ready for harvest."
2040 IF fed<pop THEN LET m$=STR$ (pop-fed)+" people will starve."
2045 IF feed>3*pop THEN LET m$="Extra food gives no bonus."
2050 IF left<0 THEN LET ok=0: LET m$="Grain short by "+STR$ (-left)
2060 IF plant>2*fed THEN LET ok=0: LET m$="Too few fed workers."
2070 IF plant>land THEN LET ok=0: LET m$="Planting exceeds your land."
2090 CLS
2100 PRINT AT 0,1; INK 6; BRIGHT 1;"YEARFALL";AT 0,20;"YEAR ";yr
2110 PRINT AT 2,1; INK 5;"PEOPLE ";pop;AT 2,17;"LAND ";land
2120 PRINT AT 3,1; INK 5;"GRAIN ";grain
2130 PRINT AT 5,1; INK 4;"PLAN";AT 5,17;"AMOUNT";AT 5,25;"COST"
2150 PRINT AT 8,1;"F Feed grain";AT 8,17;feed;AT 8,25;feed
2160 PRINT AT 9,1;"P Plant acres";AT 9,17;plant;AT 9,25;plant
2170 PRINT AT 11,1; INK 6;"Grain left: ";left
2180 PRINT AT 12,1;"Food needed: ";3*pop
2200 PRINT AT 14,1;"Fed workers can plant: ";2*fed
2210 PRINT AT 16,1; INK 6;m$
2230 PRINT AT 19,1; INK 5;"F/P edit food and planting."
2240 PRINT AT 20,1;"SPACE harvest. R reset. Q quit."
2250 RETURN
4000 CLS
4010 PRINT AT 0,1; INK 6; BRIGHT 1;"YEARFALL";AT 0,18;"HARVEST ";yr
4020 PRINT AT 2,1;"Yield: ";crop;" grain per acre"
4030 PRINT AT 4,1; INK 5;"GRAIN ACCOUNT"
4040 PRINT AT 6,1;"At start";AT 6,23;oldgrain
4060 PRINT AT 8,1;"Food spent";AT 8,23;feed
4070 PRINT AT 9,1;"Seed spent";AT 9,23;plant
4080 PRINT AT 10,1;"Harvest added";AT 10,23;harvest
4090 PRINT AT 12,1; INK 6;"Grain in store";AT 12,23;grain
4100 PRINT AT 14,1;"People lost: ";deaths
4110 PRINT AT 15,1;"Newcomers: ";newcomers
4120 PRINT AT 16,1; INK 5;"People ";oldpop;" -> ";pop
4130 PRINT AT 17,1; INK 5;"Land ";oldland;" -> ";land
4140 PRINT AT 19,1;"SPACE continues. R restarts."
4150 PRINT AT 20,1;"Q quits."
4160 RETURN
5000 CLS
5010 PRINT AT 2,10; INK 6; BRIGHT 1;"YEARFALL"
5020 PRINT AT 5,2;"Years completed: ";yr
5030 PRINT AT 7,2;"People: ";pop;" (started at 60)"
5040 PRINT AT 8,2;"Grain: ";grain
5050 PRINT AT 9,2;"Land: ";land
5060 PRINT AT 11,2;"People lost over run: ";lost
5070 LET m$="A settlement still standing."
5080 IF lost=0 THEN LET m$="Nobody has starved."
5090 IF lost=0 AND grain>=3*pop THEN LET m$="Growing, with grain in reserve."
5100 IF pop=0 THEN LET m$="The settlement is empty."
5110 PRINT AT 14,1; INK 6;m$
5120 IF pop>0 THEN PRINT AT 16,2;"Next year's food: ";3*pop
5130 PRINT AT 19,1;"R new settlement. Q quits."
5140 GO SUB 8000
5150 IF k$="q" OR k$="Q" THEN STOP
5160 IF k$="r" OR k$="R" THEN GO TO 200
5170 GO TO 5140
6000 LET d$="": LET a$="Feed grain"
6020 IF edit=3 THEN LET a$="Plant acres"
6030 PRINT AT 19,0;" ";AT 20,0;" ";AT 21,0;" "
6040 PRINT AT 19,1; INK 6;a$;": ";d$;"_ "
6050 PRINT AT 20,1;"Digits, ENTER. DELETE erases."
6060 PRINT AT 21,1;"X cancels. Blank keeps plan."
6070 GO SUB 8000
6080 IF k$="x" OR k$="X" THEN RETURN
6090 IF CODE k$=13 AND d$="" THEN RETURN
6100 IF CODE k$=13 THEN GO TO 6200
6110 IF CODE k$=12 AND LEN d$>0 THEN LET d$=d$( TO LEN d$-1): GO TO 6040
6130 IF CODE k$<48 OR CODE k$>57 THEN GO TO 6070
6140 IF LEN d$>=4 THEN GO TO 6070
6170 LET d$=d$+k$: GO TO 6040
6200 LET value=VAL d$
6220 IF edit=2 THEN LET feed=value
6230 IF edit=3 THEN LET plant=value
6240 RETURN
8000 IF INKEY$<>"" THEN GO TO 8000
8010 LET k$=INKEY$
8020 IF k$="" THEN GO TO 8010
8030 RETURNRUN and commit the opening plan. With everyone fed, three newcomers arrive: INT (60/20) is three. The first report should therefore show 63 people. Space continues to year two, where the proposed food requirement becomes 189. Grain carries over from the actual harvest; it does not return to 360.
Follow the resolution order
Food and seed are spent first. Starvation removes people who lacked complete rations. The harvest is then added. Newcomers arrive only when nobody starved, at five per cent of the opening population rounded down. They join after the harvest, so they could not have worked those fields. They will need food next year.
The condition uses deaths equal to zero, rather than surplus food. Giving extra food does not increase growth. A well-fed population below twenty receives no newcomers under this rounded rule; we have not added a minimum of one.
After the report, test the ending before incrementing yr. An empty settlement ends immediately. Year ten ends after its harvest has been counted. Otherwise advance the year and construct a new affordable starting proposal from the retained resources.
Would returning to line 200 be a suitable way to begin year two?
Show the explanation
No. Line 200 recreates the initial population, grain, land, year and loss count. The next-year path bypasses it. R deliberately uses that reset path; continuing a report must not.
Play several years and compare each opening stock with the previous report. Fixed land can become a constraint as food needs grow. A run may end through starvation; surviving ten years is not guaranteed. The summary describes resources and losses rather than awarding a population target that the growth rule cannot reach.
At this checkpoint C has no action on the summary. Continued ruling is a later feature. Keep the ten-year boundary observable while we add another resource decision.
Sources
Steven Vickers, edited by Robin Bradbeer, ZX Spectrum BASIC Programming, second edition (Sinclair Research, 1983), chapter 3, chapter 7, chapter 11, chapter 13.
Run it here
This unit's program, built for you.
- Program
- yearfall.tap
- Machine
- ZX Spectrum 48K (PAL)