Tape in/out

Press RESET immediately, Sergei! 25 Nov 01 00:54, Sergei Chikalev wrote to Kirill Frolov: KF>> Serial software emulation actually worked KF>> port (rs232) on 38400. Transmission mode is half-duplex. SC> ... and more details here please?? And with the priests... There is a bug here that allows, under certain conditions, circumstances (not present during normal operation) the receive buffer overflows. The error lies in that I forgot to check for the maximum number accepted characters. And turning off the RTS signal when full there are buffers - because if hardware control is used nothing is disrupting the flow, but there is a danger. The use of hardware flow control is MANDATORY. Either bytes will be lost (half-duplex!), or a special software protocol. For example, X-modem will work. If hardware flow control is used, then it is better to connect 2 computers such that one of them has a HARDWARE PORT. For example, spec and pc. If you connect two specs through such an “emulator”, then competition will be observed (half duplex!) - data transfer will only be possible if one wants to transmit and the other listens, otherwise everything slows down. When transmitting a large number of small blocks the speed will drop significantly.Thus, to connect 2 speck-type computers you need 5 wires, even better 7 (GND, RTS, CTS, TXD, RXD, DTE, DTR). In general, you can use 3 wires so that the letters are not lost, but it will no longer be rs232. It's better to install a hardware port. ps: for those who don’t understand, the Vicomm modem also has half-duplex and bytes are also lost. Those. For use with MMD, 3 wires are sufficient. ;--------------------------------------- ; RS232 EMULATOR ZX-LINK ; TXPORT EQU #CFF7 RXMAX EQU 270 ZXL_INI LD A,1 JR ZXL_CTL ZXL_OFF XOR A ZXL_CTL ;LD (ZXL_DCD),A AND #01 RLCA RLCA LD (TXMASK),A IN A,(#1F) RLCA RLCA RLCA AND #01 RET ; LINE SCAN BC=SIZE D=SPEED CY=NOTHING LSCAN DI PUSH IX PUSH IY LD HL,RXMAX LD DE,RXBYTE PUSH DE LD IX,(M_BUFF) LD IY,TXMASK LD BC,TXPORT LD A,(TXMASK) OR#20 OUT(C),A RXNEXT LD D,#9F ; TIME RXWAIT IN A,(#FE) R.L.A. RET C IN A,(#FE) ; 25..34 ~40 R.L.A. RET C IN A,(#FE) R.L.A. RET C IN A,(#FE) R.L.A. RET C IN A,(#FE) R.L.A. RET C IN A,(#FE) R.L.A. RET C IN A,(#FE) R.L.A. RET C IN A,(#FE) R.L.A. RET C DEC D JP NZ,RXWAIT ; +14 IN A,(#FE) RLA RET C LD A,(TXMASK) LD E,A ; +17 IN A,(#FE) RLA RET C OUT (C),E ; +12 IN A,(#FE) RLA RET C LD D,#7 ; +7 IN A,(#FE) RLA RET C RXWAIT1 IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C IN A,(#FE) RLA RET C DEC D JP NZ,RXWAIT1 RXEND POP BC EX DE,HL LD HL,RXMAX OR A SBC HL,DE POP IY POP IX JR NZ,RXOK LD BC,#0101 XOR A INC A SCF RET RXOK LD D,LINKSPEED LD B,H LD C,L XOR A INC A RET RXBYTE IN A,(#FE) RLA JR C,RXBYTE1 DEC SP DEC SP JP RXWAIT RXBYTE1 JR $+2 JR $+2 JR $+2 JR $+2 NOP IN A,(#FE) ; B0 RLA RR E DEC HL LD A,H OR L CP 1 SBC A,A CPL AND #20 OR (IY) OUT (C), A IN A,(#FE) ; B1 RLA RR E LD BC,RXBYTE PUSH BC LD BC,TXPORT JR $+2 JR $+2 JR $+2 IN A,(#FE) ; B2 RLA RR E JR $+2 JR $+2 JR $+2 JR $+2 JR $+2 NOP NOP IN A,(#FE) ; B3 RLA RR E JR $+2 JR $+2 JR $+2 JR $+2 JR $+2 NOP NOP IN A,(#FE) ; B4 RLA RR E JR $+2 JR $+2 JR $+2 JR $+2 JR $+2 NOP NOP IN A,(#FE) ; B5 RLA RR E JR $+2 JR $+2 JR $+2 JR $+2 JR $+2 NOP NOP IN A,(#FE) ; B6 RLA RR E JR $+2 JR $+2 JR $+2 JR $+2 JR $+2 NOP NOP IN A,(#FE) ; B7 RLA RR E JR $+2 JR $+2 JR $+2 JR $+2 JR $+2 NOP NOP IN A,(#FE) ; B STOP RLA JR C,RXERR LD A,E CPL LD (IX),A INC IX JP RXNEXT RXERR LD A,(TXMASK) OUT (C),A JP RXEND ; SEND BLOCK IN MDMBUFF BC=SIZE LTRANS DI PUSH IX LD E,C LD D,B LD IX,(M_BUFF) LD BC,TXPORT TXBYTE LD A,(TXMASK) OR #08 OUT (C),A LD A,(IX) CPL LD L,A LD H,8 JR $+2 LD A,0 TXBIT RR L SBC A,A AND #08 OR 0 TXMASK EQU $-1 OUT (C),A JP $+3 JP $+3 JP $+3 LD A,0 DEC H JR NZ,TXBIT JR $+2 LD A,0 LD A,(TXMASK) OUT (C),A JR $+2 JR $+2 JR $+2 INC IX DEC DE LD A,D OR E JR NZ,TXBYTE LD B,4 DJNZ $ POP IX RET