The BM Library

BM is a small library that ships with the debugger, in the Library folder beside it. It is a handful of convenience wrappers, nothing you couldn’t write yourself with a .byte loop, but they save the boilerplate for the common cases: turning a C# sequence into a data table, and emitting the BASIC stub.

Import it at the top of a template and call its methods where you want the bytes:

import BM = "BM.bmasm";

.sine:
    BM.Bytes(Enumerable.Range(0, 256).Select(i => (int)(128 + 127 * Math.Sin(i * Math.PI / 128))))

Every method emits its assembly at the call site, so a .byte table appears exactly where you wrote the call.

Tables

BM.Bytes

BM.Bytes(values, width = 16)
BM.Bytes(text)

Emits .byte lines, width values to a line, formatted as $XX. values is an IEnumerable of int, sbyte or byte; int and sbyte are truncated to a byte. The text overload emits one byte per character, using the raw character code with no encoding change.

BM.Words

BM.Words(values, width = 16)

Emits .word lines, little-endian, width values to a line. values is an IEnumerable of ushort or short.

BM.HighBytes / BM.LowBytes

BM.HighBytes(values, width = 16)
BM.LowBytes(values, width = 16)

Emit the high or low byte of each value as .byte lines. values is an IEnumerable of int, ushort or short. Use the pair to build split lookup tables, a run of low bytes and a matching run of high bytes, so you can index them with lda lo,x / lda hi,x:

.const count 32

.jump_lo:
    BM.LowBytes(Enumerable.Range(0, count).Select(i => targets[i]))
.jump_hi:
    BM.HighBytes(Enumerable.Range(0, count).Select(i => targets[i]))

Strings

The string helpers do no character-set translation despite the names; the bytes are the source string’s character codes.

BM.Petscii

BM.Petscii(text, addNullTermination = true)

Emits one byte per character of text, followed by a 0 unless you pass addNullTermination: false.

.message:
    BM.Petscii("HELLO WORLD")

BM.IsoPetscii

BM.IsoPetscii(text, addNullTermination = true)

As BM.Petscii, but each character in the range $40 to $5f (@ to _) is shifted down by $40 first.

BM.StringToPetscii

BM.StringToPetscii(text, addNullTermination = true)

Returns those bytes as an IEnumerable<byte> rather than emitting them. Transform or filter it, or hand it to BM.Bytes.

BASIC header

BM.X16Header

BM.X16Header()
BM.X16Header(label, invalidHeader = false)

Emits the tokenised BASIC line that makes RUN enter your machine code.

With no argument it emits 10 SYS 2061 in twelve bytes, so your first instruction has to sit at $080d, straight after the header:

import BM = "BM.bmasm";

    BM.X16Header()
.proc main          ; $080d
    rts
.endproc

Given a label it emits 10 SYS <label> instead, so the entry point can be anywhere. Pass the label as a name, which the compiler resolves, or as a literal address:

    BM.X16Header("start")
    ; tables or setup here
.start:
    ; ...

The helper writes the address as exactly four decimal digits, so label must be below 10000 ($2710); a higher address is silently truncated and the SYS comes out wrong. invalidHeader: true drops the trailing two-byte end-of-program marker, leaving a ten-byte header.