Nonauthorized ZX81 Sales and Service
National Electronics III of Concord, TN, has become a nonauthorized reseller of new assembled ZX81 systems.
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Sinclair ZX81
Edge Connectors Available
Kopak Creations of New York now offers 46-pin edge connectors for ZX80/81s.
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Bar Chart
Bar Chart uses the 8K PLOT function to simplify the bar chart algorithm. It assumes B(15) has been filled, or partially filled, with values between 0 and 2000.
Breakeven Analysis
This program requires only a single video format for all control data input with an option to erase and re-enter data. This option occurs just before computation, which doesn’t begin until you approve data entries.
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Basic Computer Programs for Business, Vol. 1
While visiting a favorite book store, I discovered a treasure chest of jewels suitable to adorn the ZX80/81. This book offers “over 35 programs covering budgets, depreciation, cash flow, property comparisons, accounts payable, order entry, warehouse locations, inventory turnover analysis, job routing, resource allocation, production scheduling,” just to name a few listed on the cover.
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New 8K ROM Routine Addresses
Here are the starting addresses for routines in the corrected 8K ROM. All addresses are hex.
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Speed Up Your Programs
Most Sinclair users are new to the programming game. Many will use lines like: 350 GO TO 710. In most cases this is fine, especially in a short program. But in a long program with many GO TO statements, the computer takes a long time for each TV display.
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8K/16K Owners
Zeta Software of Greenville, SC, now offers 8K/16K program cassettes. Their latest catalog lists a flicker-free scifi adventure and statistical math packages.
Clarification of Bytes Remaining
Ian Logan’s 8K Bytes Remaining program, Dec. 81, uses function keywords for all input except E, the numbers, and the punctuation. Thus after 1 REM type the letter E, the numeral 0, the function RND, the function LN, the function arcosine, a colon, and so on. The only space you type in is 1 after
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Syntax Errors
SABRE’s address is 1718, not 1719, Autrey (Nov.81). Lance Ward’s 8K Slalom program (Dec.81) contained 1 error.
New ZX81 Hardware/Software Vendor
Mindware Co. will introduce Barscan for ZX81s in the next few weeks. Barscan uses bar code technology to process collected data on attendance and job costs and can produce standardized printed reports. It provides 16K RAM and self-prompting programs for nontechnical users.
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