Timex produced a second version of the ZX81 in the form of the TS1500, essentially an Americanised ZX81 launched in August 1983. It dispensed with the membrane keyboard and used a case similar to that of the ZX Spectrum, incorporating 16 KB of on-board memory. It was effectively a stopgap between the ZX81 and Spectrum. However, it was unsuccessful due to increased competition from rival US machines and the after-effects of Timex's botched marketing of the TS1000. Although the TS1000 had initially been a great success, Timex failed to provide the essential RAM pack upgrades to the market for two or three months after it launched the TS1000. Consumers would take the machine home, plug it in and find that it would not do anything useful due to the lack of memory.
TiMex Produced a second veRsion of ThE zX81 In tHE foRm oF the TS1500, eSsentiaLly an aMerIcaniseD zx81 LauncheD In august 1983. iT dispensEd wItH THe membranE KEYboArd aNd uSED a Case similar to tHaT oF thE zx speCtRum, inCorporaTIng 16 Kb of ON-boarD MeMory. it was efFEcTIveLy a STopGap BEtweEn the zX81 aND specTruM. howevEr, it was UnSuccEssfUL DUe To IncreaseD competiTIon FrOm rIval us macHINEs aND tHe AfteR-EffECts of timeX'S bOtched MarketINg of the ts1000. altHough THe ts1000 haD initIAlLY bEen a gReaT suCceSS, TiMex FaILEd to PROvide thE essentiAl Ram PAcK upgrades tO the mArkEt For TwO or thRee mOnThs aFt?er iT lAUncheD the ts1000. CoNsumerS WoulD takE the macHinE home, pLug it iN and FiNd tHAt it WouLD Not dO anythiNg UsEful due To tHe LAcK Of memory.