4Data Telesoftware Adaptor Issue 1.2: Routine at 1D66

1D66: buffers_in_screen: Reposition the page receive buffer at $4840 and the page display buffer at $5000 (within screen RAM).

Used by the routine at telesoftware_main.
buffers_in_screen	1D66	LD HL,$4840	Set page_receive_buffer_pointer to $4840 and page_display_buffer_pointer to $5000.
	1D69	LD (page_receive_buffer_pointer),HL
	1D6C	LD HL,$5000
	1D6F	LD (page_display_buffer_pointer),HL
	1D72	XOR A	Clear attributes for row 1-23 to 0 (black on black).
	1D73	LD HL,$5820
	1D76	LD DE,$5821
	1D79	LD (HL),A
	1D7A	LD BC,$02DF
	1D7D	LDIR
	1D7F	LD HL,($5CB4)	OR P_RAMT with $7FFF and store result in telesoftware_RAMT.
	1D82	LD A,$FF
	1D84	LD L,A
	1D85	RES 7,A
	1D87	OR H
	1D88	LD H,A
	1D89	LD (telesoftware_RAMT),HL
	1D8C	XOR A	Set blocks_remaining to zero.
	1D8D	LD (blocks_remaining),A	Set blocks_remaining to zero.
	1D90	LD HL,$4800	Clear 64 bytes at $4800 and return.
	1D93	LD DE,$4801
	1D96	LD (HL),A
	1D97	LD BC,$003F
	1D9A	LDIR
	1D9C	RET