Block Data Transfer

RAM MEMORY

510 GOSUB 2000

Retrieve variables

This subroutine stores variables CF, JC, and AC into an array starting in segment 1, address 0.

1000 POK EB1, 30*NO, JC

1010 POKEW1,30*NO+ 1,AC

1020 POKEF1,30*NO+ 3,CF

1030 POKE$1, 30*NO+ 9,$(0)

1040 RETURN

Subroutine 2000 - 2040 retrieves data into variables CF, JC and AC .

2000 JC =		PEEKB(1,30*NO)
2010	AC =	PEEKW (1,30*N O+ 1)
2020	$(1) =	PEEK$(1, 30*NO+ 9)
2030 CF =		PEEKF (1,30*N O+ 3)

2040 RETURN

You can store and retrie ve strings a nd variab les in this way. Ther e are many variations of PEEK and POKE statements. Refer to the RPBASIC -52 Software Supplement in this manual for additional information and examp les. A list of comm ands appea rs at the end of this chapter .

Blocks of data are transferred to and from RA M and flash EPR OM u sing BLOAD and BSAVE comma nds. Block transfers are useful for loading and storing data, look-up tables, text, etc. U p to 65,535 bytes can be moved from RAM to EPROM or EPROM to RAM at one time. The absolute number of bytes that are moved is limited by the RAM and EPR OM sizes.

Transfers from EPRO M to RAM , using BLOA D, take approximately 23.5 m s/1000 bytes. T ransfers from RAM to EPROM , using BSAVE , are even longer at 100 ms/ 1000 bytes usin g a 512K byte EPR OM . T his time is even longer when smaller E PROM s are used (due to the program ming algorithm).

Serial port, tick timer, and external interrupts are enabled dur ing these tra nsfers. Howe ver, response s to ONT ICK or ONIT R are d elayed by the time it takes to transfer data. W hen ONTIC K or ONIT R must be serviced faster, transfer data in sm aller blocks.

Refer to BLOAD and BSAVE in Appendix A for more information.

SECTION 5

ASSEMBLY LANGUAGE INTERFACE

Assembly language program s must be placed in the RPBASIC-52 E PROM . W hen using RPBASIC-52, progr ams shou ld start at addr ess 6000H or higher up to 7FFFH .

RPBASIC is norm ally in a 32K byte EPROM (27C256). A 64K byte EPROM (27C512) may be used in socket U4 provided the following modification is made: Cut the trace between W11 pins 1 and 2 on the circuit side. (Jumper W11 is under socket U4. P in 1 is designated by the square pad.) Solder a jumpe r between W11 pin 2 and 3.

Docum ented assem bly language interface calls listed in the Intel MCS BASIC -52 Users Manual will not work with RPBASIC-52. This is because RPBASIC-52 has been reassembled and code shifted around.

The RP-10 adapter boar d is used to run and debug assembly and C code. This board plugs into RAM socket U5 and RPBASIC socket U4. It does not use the Basic at all.

COMMANDS

The following is a list of RPBASIC-52 commands used w it h R A M .

Comm and	Function
BLOAD	Transfers data from EPROM to RAM
BSAVE	Transfers data from RAM to EPROM
CALL	Calls an assembly language routine
CBY	Return s code m emor y data
DBY	Returns or assigns internal memory
MTOP	Sets top of RAM memory
PEEK B	Return s a byte
PEEK F	Returns a floating point number
PEEK W Returns a 16 bit value
PEEK $	Returns a string
POKE B	Stores a by te
POKE F Stores a floating point number
POKE W Stores a 16 bit value
POKE $	Stores a string
XBY	Returns or assigns external memory

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