Tandy's Little Wonder (1993)(Farna Systems).pdf - TRS-80 Color ...

CoCo Clones... an attempt to ride Tandy's wake...There were only three CoCo clones ever made. The mostknown in the U.S. is the Dragon Systems Ltd. (a Britishcompany) "Dragon", imported to the U.S. by Tano. Asecond clone was advertised in Byte Magazine, the SampoColor Computer (made in Korea), but never made it to thesales floor. It is quite possible that the ROMs used were nearduplicates (if not blatantly so!) of the Tandy code, and thatTandy therefore prevented importation. Until four to fiveyears ago, U.S. copyrights weren't protected in most Asiancountries, including Japan and Korea. One could walk into aKorean computer store and find hundreds of copies ofcommercial software for share-ware prices... averaging $5per disk, plus $5-$10 for a manual.The third "clone" was not really a clone at all, but an attemptto make an improved but downwardly compatible computer.The FHL TC9 used a 68B09 and GIME just like the CoCo3, but had some improved hardware design. It was intendedto primarily be an OS-9 platform.The Dragon Systems/Tano DragonThe following article was originally written for the Octoberissue of Color Computer News by Alfredo Santos butnever appeared due to the magazines discontinuance.page 34Enter The Dragon/64Alfredo Santos September 30, 1983The Dragon/64 computer, which is enjoying great successin England, is now available in America. What makes theDragon worthy of mention in this magazine is the fact that ituses a 6809E microprocessor and Microsoft BASIC justlike our friend the TRS-80 Color Computer.When I first heard about the Dragon/64 (and little brotherDragon/32) my first question was: "Will Color Computerprograms run on the Dragon?". The answer is YES... and NO!The incompatibility of BASIC word tokens between the 2machines prevent CoCo programs from working on theDragon, but not to worry! If you save a CoCo program usingthe ASCII format (i.e.: CSAVE "filename",A) it will CLOADand RUN on the Dragon with little or no problem. Problemsmay occur if any memory locations in low RAM are PEEKedor POKEd and problems will occur for sure if any CoCoROM routines are called.Here’s why: Dragons' Color BASIC and Extended ColorBASIC are identical to CoCos' in many ways with somemajor exceptions. Both are burned into a singleHN4827128G-30 28 pin EPROM. While the Dragons'BASIC chip (IC 18) occupies memory locations &H8000-&HBFFF like the CoCo, ROM entry points are different.CoCo’s POLLCAT routine, for instance, is at &HA1C1while on the Dragon it’s at &HBBE5. This fact preventsTandy's Little WonderColor Computer machine language programs from runningon the Dragon unmodified.Dragon ROM entry points and CoCo BASIC equivalents:CoCo DragonAddress Address Comment(A000) A1C1 (A000) 8006 POLL KEY(A002) A282 (A002) B54A CHAR OUT (cass)(A004) A77C (A004) 8021 CASS READ(A006) A70B (A006) B93E BLOCK IN(A008) A7F4 (A008) B999 BLOCK OUT(A00A) A9DE (A00A) 8012 READ IN JOYSTK VAL(A00C) A7D8 (A00C) 801B HEADER OUTBoth the CoCo and Dragon have indirect addresses at &HA000-&HA00C- theDragon’s bid at CoCo compatibility.894C9D395CFA95DA00E B39B SECONDARY RESETA027 B3B4 MAIN RESETA02A B3B7A06EHARD STARTA0E8 B44F SOFT STARTA176 B50A CHAR INA186B51AA1B1B538A1C1 BBE5 CHECK KEYBRDA282 B54A CHAR OUT (cass)A290B560A2A8 B578A2BF BD1AA30A BCAB CHAR OUT (screen)A34B BCE2 SCROLL UP ONE LINEA390 B5C6 INPUT FROM KEYBRDA393B5C9A398B5CEA42DB663A444B67AA46C B6A8A491B6CDA502A095A59A B7CC Data mover routineA5EEB820A619B84BA629B85BA635B867A65CB88EA65FB891A663B895A701B933A70B B93E BLOCK INA77C BDE7 Cass. READ outA7E9BDDCA7D1B480A7D3B482A7D8BE68A7F4 B999 BLOCK OUTA928 BA77 Clear ScreenA951BAA0A956BAA5A974BAC3A976 BAC5 sound routineA9DEBD52AD19 8417 Clear mem (NEW+3)B277 89B4 get operandB99C 90E5 PRINT text string